During the second half of `test_all_l10n`, we keep deleting `account.account` records (hundreds to low thousand every iteration). This deletion turns out to account (heh) for about 15% of the test's run time running locally (5mn out of 30). And per the explain, this is largely from executing `ON DELETE` constraints: since accounts are rarely deleted, the forward-only M2Os (used to go from a record to an account) are not generally indexes, which causes a full scan of the non-account table on deletion of accounts, which... can be quite slow if the non-account table is large, e.g. sample `EXPLAIN ANALYZE` for one of the `DELETE FROM account_account`:

    Trigger for constraint account_fiscal_position_account_account_src_id_fkey on account_account: time=30.040 calls=1000
    Trigger for constraint account_fiscal_position_account_account_dest_id_fkey on account_account: time=20.977 calls=1000
    Trigger for constraint account_account_tax_default_rel_account_id_fkey on account_account: time=16.423 calls=1000
    Trigger for constraint account_account_res_company_rel_account_account_id_fkey on account_account: time=18.848 calls=1000
    Trigger for constraint account_account_account_tag_account_account_id_fkey on account_account: time=12.396 calls=1000
    Trigger for constraint account_journal_default_account_id_fkey on account_account: time=207.759 calls=1000
    Trigger for constraint account_journal_suspense_account_id_fkey on account_account: time=131.019 calls=1000
    Trigger for constraint account_journal_non_deductible_account_id_fkey on account_account: time=126.656 calls=1000
    Trigger for constraint account_journal_profit_account_id_fkey on account_account: time=128.753 calls=1000
    Trigger for constraint account_journal_loss_account_id_fkey on account_account: time=125.281 calls=1000
    Trigger for constraint res_company_transfer_account_id_fkey on account_account: time=85.604 calls=1000
    Trigger for constraint res_company_default_cash_difference_income_account_id_fkey on account_account: time=75.154 calls=1000
    Trigger for constraint res_company_default_cash_difference_expense_account_id_fkey on account_account: time=73.173 calls=1000
    Trigger for constraint res_company_account_journal_suspense_account_id_fkey on account_account: time=73.336 calls=1000
    Trigger for constraint res_company_account_journal_early_pay_discount_gain_accoun_fkey on account_account: time=73.741 calls=1000
    Trigger for constraint res_company_account_journal_early_pay_discount_loss_accoun_fkey on account_account: time=73.402 calls=1000
    Trigger for constraint res_company_income_currency_exchange_account_id_fkey on account_account: time=74.586 calls=1000
    Trigger for constraint res_company_expense_currency_exchange_account_id_fkey on account_account: time=74.678 calls=1000
    Trigger for constraint res_company_account_default_pos_receivable_account_id_fkey on account_account: time=77.105 calls=1000
    Trigger for constraint res_company_expense_accrual_account_id_fkey on account_account: time=77.000 calls=1000
    Trigger for constraint res_company_revenue_accrual_account_id_fkey on account_account: time=76.399 calls=1000
    Trigger for constraint res_company_account_cash_basis_base_account_id_fkey on account_account: time=77.996 calls=1000
    Trigger for constraint res_company_account_discount_income_allocation_id_fkey on account_account: time=77.799 calls=1000
    Trigger for constraint res_company_account_discount_expense_allocation_id_fkey on account_account: time=78.145 calls=1000
    Trigger for constraint res_company_income_account_id_fkey on account_account: time=79.625 calls=1000
    Trigger for constraint res_company_expense_account_id_fkey on account_account: time=79.421 calls=1000
    Trigger for constraint account_tax_group_tax_payable_account_id_fkey on account_account: time=103.659 calls=1000
    Trigger for constraint account_tax_group_tax_receivable_account_id_fkey on account_account: time=75.211 calls=1000
    Trigger for constraint account_tax_group_advance_tax_payment_account_id_fkey on account_account: time=72.384 calls=1000
    Trigger for constraint account_tax_cash_basis_transition_account_id_fkey on account_account: time=954.139 calls=1000
    Trigger for constraint account_tax_repartition_line_account_id_fkey on account_account: time=1445.578 calls=1000
    Trigger for constraint account_reconcile_model_line_account_id_fkey on account_account: time=71.619 calls=1000
    Trigger for constraint account_move_line_account_id_fkey on account_account: time=140.720 calls=1000
    Trigger for constraint account_payment_outstanding_account_id_fkey on account_account: time=17.682 calls=1000
    Trigger for constraint account_payment_destination_account_id_fkey on account_account: time=6.791 calls=1000
    Trigger for constraint account_payment_method_line_payment_account_id_fkey on account_account: time=75.530 calls=1000
    Trigger for constraint account_analytic_line_general_account_id_fkey on account_account: time=81.989 calls=1000
    Trigger for constraint account_automatic_entry_wizard_destination_account_id_fkey on account_account: time=8.967 calls=1000
    Trigger for constraint account_payment_register_writeoff_account_id_fkey on account_account: time=9.166 calls=1000
    Trigger for constraint account_accrued_orders_wizard_account_id_fkey on account_account: time=7.863 calls=1000
    Trigger for constraint account_account_account_merge_wizard_re_account_account_id_fkey on account_account: time=7.338 calls=1000
    Trigger for constraint account_merge_wizard_line_account_id_fkey on account_account: time=7.706 calls=1000
    Trigger for constraint res_company_deferred_expense_account_id_fkey on account_account: time=126.271 calls=1000
    Trigger for constraint res_company_deferred_revenue_account_id_fkey on account_account: time=98.607 calls=1000
    Trigger for constraint account_account_account_auto_reconcile__account_account_id_fkey on account_account: time=8.921 calls=1000
    Trigger for constraint account_reconcile_wizard_account_id_fkey on account_account: time=8.330 calls=1000
    Trigger for constraint account_model_rel_account_account_id_fkey on account_account: time=27.264 calls=1000
    Trigger for constraint account_transfer_model_line_account_id_fkey on account_account: time=39.033 calls=1000
    Trigger for constraint account_fiscal_position_avatax_invoice_account_id_fkey on account_account: time=83.360 calls=1000
    Trigger for constraint account_fiscal_position_avatax_refund_account_id_fkey on account_account: time=60.023 calls=1000
    Trigger for constraint account_account_account_import_summary__account_account_id_fkey on account_account: time=8.251 calls=1000
    Trigger for constraint res_company_account_revaluation_expense_provision_account__fkey on account_account: time=107.339 calls=1000
    Trigger for constraint res_company_account_revaluation_income_provision_account_i_fkey on account_account: time=100.037 calls=1000
    Trigger for constraint account_account_exclude_res_currency_pr_account_account_id_fkey on account_account: time=9.025 calls=1000
    Trigger for constraint account_report_budget_item_account_id_fkey on account_account: time=7.600 calls=1000
    Trigger for constraint account_payment_withholding_line_account_id_fkey on account_account: time=7.814 calls=1000
    Trigger for constraint res_company_withholding_tax_base_account_id_fkey on account_account: time=116.893 calls=1000
    Trigger for constraint account_payment_register_withholding_outstanding_account_i_fkey on account_account: time=8.580 calls=1000
    Trigger for constraint account_payment_register_withholding_line_account_id_fkey on account_account: time=8.799 calls=1000
    Trigger for constraint res_company_l10n_ee_rounding_difference_loss_account_id_fkey on account_account: time=115.461 calls=1000
    Trigger for constraint res_company_l10n_ee_rounding_difference_profit_account_id_fkey on account_account: time=114.827 calls=1000
    Trigger for constraint account_journal_l10n_tr_default_sales_return_account_id_fkey on account_account: time=305.506 calls=1000
    Trigger for constraint res_company_account_production_wip_account_id_fkey on account_account: time=125.388 calls=1000
    Trigger for constraint res_company_account_production_wip_overhead_account_id_fkey on account_account: time=117.769 calls=1000
    Trigger for constraint stock_location_valuation_in_account_id_fkey on account_account: time=104.378 calls=1000
    Trigger for constraint stock_location_valuation_out_account_id_fkey on account_account: time=67.309 calls=1000
    Trigger for constraint stock_valuation_layer_revaluation_account_id_fkey on account_account: time=8.817 calls=1000
    Trigger for constraint res_company_l10n_fr_rounding_difference_loss_account_id_fkey on account_account: time=127.732 calls=1000
    Trigger for constraint res_company_l10n_fr_rounding_difference_profit_account_id_fkey on account_account: time=124.773 calls=1000
    Trigger for constraint res_company_l10n_in_withholding_account_id_fkey on account_account: time=124.847 calls=1000
    Trigger for constraint res_company_l10n_nl_rounding_difference_loss_account_id_fkey on account_account: time=131.094 calls=1000
    Trigger for constraint res_company_l10n_nl_rounding_difference_profit_account_id_fkey on account_account: time=132.013 calls=1000
    Trigger for constraint mrp_workcenter_expense_account_id_fkey on account_account: time=14.578 calls=1000
    Trigger for constraint mrp_account_wip_accounting_line_account_id_fkey on account_account: time=8.530 calls=1000
    Trigger for constraint account_payment_force_outstanding_account_id_fkey on account_account: time=11.336 calls=1000
    Trigger for constraint pos_payment_method_outstanding_account_id_fkey on account_account: time=11.554 calls=1000
    Trigger for constraint pos_payment_method_receivable_account_id_fkey on account_account: time=6.654 calls=1000
    Trigger for constraint pos_close_session_wizard_account_id_fkey on account_account: time=7.825 calls=1000
    Trigger for constraint res_company_downpayment_account_id_fkey on account_account: time=137.312 calls=1000
    Trigger for constraint res_company_l10n_bd_corporate_tax_liability_fkey on account_account: time=143.026 calls=1000
    Trigger for constraint res_company_l10n_bd_corporate_tax_expense_fkey on account_account: time=141.801 calls=1000
    Trigger for constraint account_move_l10n_de_datev_main_account_id_fkey on account_account: time=3874.682 calls=1000
    Trigger for constraint stock_landed_cost_lines_account_id_fkey on account_account: time=14.898 calls=1000
    Trigger for constraint account_account_account_asset_rel_account_account_id_fkey on account_account: time=9.640 calls=1000
    Trigger for constraint account_asset_account_asset_id_fkey on account_account: time=11.687 calls=1000
    Trigger for constraint account_asset_account_depreciation_id_fkey on account_account: time=6.551 calls=1000
    Trigger for constraint account_asset_account_depreciation_expense_id_fkey on account_account: time=6.300 calls=1000
    Trigger for constraint res_company_gain_account_id_fkey on account_account: time=210.699 calls=1000
    Trigger for constraint res_company_loss_account_id_fkey on account_account: time=180.965 calls=1000
    Trigger for constraint asset_modify_account_asset_id_fkey on account_account: time=10.665 calls=1000
    Trigger for constraint asset_modify_account_asset_counterpart_id_fkey on account_account: time=5.466 calls=1000
    Trigger for constraint asset_modify_account_depreciation_id_fkey on account_account: time=5.353 calls=1000
    Trigger for constraint asset_modify_account_depreciation_expense_id_fkey on account_account: time=5.438 calls=1000
    Trigger for constraint res_company_l10n_ae_tax_report_liabilities_account_fkey on account_account: time=176.808 calls=1000
    Trigger for constraint res_company_l10n_ae_tax_report_expenses_account_fkey on account_account: time=172.302 calls=1000
    Trigger for constraint res_company_l10n_ae_tax_report_asset_account_fkey on account_account: time=170.480 calls=1000
    Trigger for constraint res_company_l10n_ar_tax_base_account_id_fkey on account_account: time=171.774 calls=1000
    Trigger for constraint soda_account_mapping_account_id_fkey on account_account: time=9.239 calls=1000
    Trigger for constraint res_company_l10n_ec_tax_base_sale_account_id_fkey on account_account: time=176.779 calls=1000
    Trigger for constraint res_company_l10n_ec_tax_base_purchase_account_id_fkey on account_account: time=175.159 calls=1000
    Trigger for constraint account_loan_long_term_account_id_fkey on account_account: time=13.823 calls=1000
    Trigger for constraint account_loan_short_term_account_id_fkey on account_account: time=7.044 calls=1000
    Trigger for constraint account_loan_expense_account_id_fkey on account_account: time=5.934 calls=1000
    Trigger for constraint res_company_l10n_cl_factoring_counterpart_account_id_fkey on account_account: time=193.722 calls=1000
    Trigger for constraint res_company_exemption_doctor_master_account_id_fkey on account_account: time=201.309 calls=1000
    Trigger for constraint res_company_exemption_bachelor_account_id_fkey on account_account: time=200.476 calls=1000
    Trigger for constraint res_company_exemption_bachelor_capping_account_id_fkey on account_account: time=200.465 calls=1000
    Trigger for constraint res_company_partner_id_fkey on res_company: time=0.208 calls=10
    Trigger for constraint res_company_currency_id_fkey on res_company: time=0.018 calls=10
    Trigger for constraint res_company_paperformat_id_fkey on res_company: time=0.014 calls=10
    Trigger for constraint res_company_create_uid_fkey on res_company: time=0.015 calls=10
    Trigger for constraint res_company_write_uid_fkey on res_company: time=0.009 calls=10
    Trigger for constraint res_company_resource_calendar_id_fkey on res_company: time=0.023 calls=10
    Trigger for constraint res_company_transfer_account_id_fkey on res_company: time=0.002 calls=9
    Trigger for constraint res_company_default_cash_difference_income_account_id_fkey on res_company: time=0.055 calls=10
    Trigger for constraint res_company_default_cash_difference_expense_account_id_fkey on res_company: time=0.030 calls=10
    Trigger for constraint res_company_account_journal_suspense_account_id_fkey on res_company: time=0.002 calls=8
    Trigger for constraint res_company_account_journal_early_pay_discount_gain_accoun_fkey on res_company: time=0.002 calls=7
    Trigger for constraint res_company_account_journal_early_pay_discount_loss_accoun_fkey on res_company: time=0.001 calls=4
    Trigger for constraint res_company_income_currency_exchange_account_id_fkey on res_company: time=0.029 calls=10
    Trigger for constraint res_company_expense_currency_exchange_account_id_fkey on res_company: time=0.001 calls=5
    Trigger for constraint res_company_batch_payment_sequence_id_fkey on res_company: time=0.016 calls=10
    Trigger for constraint res_company_account_default_pos_receivable_account_id_fkey on res_company: time=0.001 calls=2
    Trigger for constraint res_company_account_fiscal_country_id_fkey on res_company: time=0.015 calls=10
    Trigger for constraint res_company_income_account_id_fkey on res_company: time=0.002 calls=6
    Trigger for constraint res_company_expense_account_id_fkey on res_company: time=0.001 calls=3
    Trigger for constraint res_company_deferred_expense_account_id_fkey on res_company: time=0.000 calls=1
    Trigger for constraint res_company_nomenclature_id_fkey on res_company: time=0.012 calls=10
    Trigger for constraint res_company_internal_transit_location_id_fkey on res_company: time=0.014 calls=10
    Trigger for constraint res_company_stock_mail_confirmation_template_id_fkey on res_company: time=0.013 calls=10
    Trigger for constraint res_company_documents_fleet_folder_fkey on res_company: time=0.016 calls=10
    Trigger for constraint res_company_documents_hr_folder_fkey on res_company: time=0.010 calls=10
    Trigger for constraint res_company_documents_employee_folder_id_fkey on res_company: time=0.011 calls=10
    Trigger for constraint res_company_documents_project_folder_id_fkey on res_company: time=0.009 calls=10
    Trigger for constraint res_company_stock_sms_confirmation_template_id_fkey on res_company: time=0.012 calls=10
    Trigger for constraint res_company_recruitment_folder_id_fkey on res_company: time=0.010 calls=10
    Trigger for constraint res_company_project_time_mode_id_fkey on res_company: time=0.019 calls=10
    Trigger for constraint res_company_timesheet_encode_uom_id_fkey on res_company: time=0.011 calls=10
    Trigger for constraint res_company_internal_project_id_fkey on res_company: time=0.015 calls=10
    Trigger for constraint res_company_leave_timesheet_task_id_fkey on res_company: time=0.015 calls=10
    Trigger for constraint res_company_rental_loc_id_fkey on res_company: time=0.011 calls=10
    Trigger for constraint res_company_l10n_ch_delegate_country_id_fkey on res_company: time=0.013 calls=10
    Trigger for constraint res_company_l10n_eg_annual_leave_type_id_fkey on res_company: time=0.014 calls=10

Accumulated across the entire test:

    account_account_account_asset_rel_account_account_id_fkey: 367.89
    account_account_account_auto_reconcile__account_account_id_fkey: 369.314
    account_account_account_import_summary__account_account_id_fkey: 308.894
    account_account_account_merge_wizard_re_account_account_id_fkey: 258.345
    account_account_account_tag_account_account_id_fkey: 437.58
    account_account_exclude_res_currency_pr_account_account_id_fkey: 364.079
    account_account_res_company_rel_account_account_id_fkey: 676.195
    account_account_tax_default_rel_account_id_fkey: 616.155
    account_accrued_orders_wizard_account_id_fkey: 281.117
    account_analytic_line_general_account_id_fkey: 2920.52
    account_asset_account_asset_id_fkey: 435.021
    account_asset_account_depreciation_expense_id_fkey: 225.966
    account_asset_account_depreciation_id_fkey: 243.045
    account_automatic_entry_wizard_destination_account_id_fkey: 333.281
    account_fiscal_position_account_account_dest_id_fkey: 764.004
    account_fiscal_position_account_account_src_id_fkey: 1127.7
    account_fiscal_position_avatax_invoice_account_id_fkey: 2903.72
    account_fiscal_position_avatax_refund_account_id_fkey: 2243.92
    account_journal_default_account_id_fkey: 8123.53
    account_journal_l10n_tr_default_sales_return_account_id_fkey: 13035
    account_journal_loss_account_id_fkey: 4810.37
    account_journal_non_deductible_account_id_fkey: 5057.85
    account_journal_profit_account_id_fkey: 5063.26
    account_journal_suspense_account_id_fkey: 5492.64
    account_loan_expense_account_id_fkey: 222.776
    account_loan_long_term_account_id_fkey: 553.955
    account_loan_short_term_account_id_fkey: 259.905
    account_merge_wizard_line_account_id_fkey: 265.135
    account_model_rel_account_account_id_fkey: 927.993
    account_move_l10n_de_datev_main_account_id_fkey: 122923
    account_move_line_account_id_fkey: 4000.68
    account_payment_destination_account_id_fkey: 265.653
    account_payment_force_outstanding_account_id_fkey: 459.209
    account_payment_method_line_payment_account_id_fkey: 2660.46
    account_payment_outstanding_account_id_fkey: 575.21
    account_payment_register_withholding_line_account_id_fkey: 319.363
    account_payment_register_withholding_outstanding_account_i_fkey: 383.508
    account_payment_register_writeoff_account_id_fkey: 341.615
    account_payment_withholding_line_account_id_fkey: 286.658
    account_reconcile_model_line_account_id_fkey: 2608.16
    account_reconcile_wizard_account_id_fkey: 309.389
    account_report_budget_item_account_id_fkey: 300.099
    account_tax_cash_basis_transition_account_id_fkey: 31329.6
    account_tax_group_advance_tax_payment_account_id_fkey: 2629.35
    account_tax_group_tax_payable_account_id_fkey: 3554.27
    account_tax_group_tax_receivable_account_id_fkey: 2772.1
    account_tax_repartition_line_account_id_fkey: 47923.3
    account_transfer_model_line_account_id_fkey: 1309.84
    asset_modify_account_asset_counterpart_id_fkey: 207.683
    asset_modify_account_asset_id_fkey: 454.126
    asset_modify_account_depreciation_expense_id_fkey: 189.258
    asset_modify_account_depreciation_id_fkey: 192.029
    mrp_account_wip_accounting_line_account_id_fkey: 305.605
    mrp_workcenter_expense_account_id_fkey: 565.317
    pos_close_session_wizard_account_id_fkey: 285.536
    pos_payment_method_outstanding_account_id_fkey: 432.131
    pos_payment_method_receivable_account_id_fkey: 249.401
    res_company_account_cash_basis_base_account_id_fkey: 5195.51
    res_company_account_default_pos_receivable_account_id_fkey: 5357.29
    res_company_account_discount_expense_allocation_id_fkey: 5113.98
    res_company_account_discount_income_allocation_id_fkey: 5151.48
    res_company_account_fiscal_country_id_fkey: 1
    res_company_account_journal_early_pay_discount_gain_accoun_fkey: 5640.61
    res_company_account_journal_early_pay_discount_loss_accoun_fkey: 5489.35
    res_company_account_journal_suspense_account_id_fkey: 5811.88
    res_company_account_production_wip_account_id_fkey: 8351.27
    res_company_account_production_wip_overhead_account_id_fkey: 7914.54
    res_company_account_revaluation_expense_provision_account__fkey: 8858.1
    res_company_account_revaluation_income_provision_account_i_fkey: 8169.02
    res_company_batch_payment_sequence_id_fkey: 0.995
    res_company_create_uid_fkey: 2.96
    res_company_currency_id_fkey: 1.081
    res_company_default_cash_difference_expense_account_id_fkey: 6060.06
    res_company_default_cash_difference_income_account_id_fkey: 6404.5
    res_company_deferred_expense_account_id_fkey: 10447.3
    res_company_deferred_revenue_account_id_fkey: 8923.24
    res_company_documents_employee_folder_id_fkey: 0.875
    res_company_documents_fleet_folder_fkey: 1.374
    res_company_documents_hr_folder_fkey: 0.829
    res_company_documents_project_folder_id_fkey: 0.779
    res_company_downpayment_account_id_fkey: 8009.08
    res_company_exemption_bachelor_account_id_fkey: 10964.3
    res_company_exemption_bachelor_capping_account_id_fkey: 10860.6
    res_company_exemption_doctor_master_account_id_fkey: 11117
    res_company_expense_account_id_fkey: 5124.13
    res_company_expense_accrual_account_id_fkey: 5246.67
    res_company_expense_currency_exchange_account_id_fkey: 5352.77
    res_company_external_report_layout_id_fkey: 0.308
    res_company_gain_account_id_fkey: 14196.4
    res_company_income_account_id_fkey: 5136.8
    res_company_income_currency_exchange_account_id_fkey: 5441.56
    res_company_internal_project_id_fkey: 1.151
    res_company_internal_transit_location_id_fkey: 1.019
    res_company_l10n_ae_tax_report_asset_account_fkey: 10908.2
    res_company_l10n_ae_tax_report_expenses_account_fkey: 11365.8
    res_company_l10n_ae_tax_report_liabilities_account_fkey: 11898.4
    res_company_l10n_ar_tax_base_account_id_fkey: 10648.4
    res_company_l10n_bd_corporate_tax_expense_fkey: 8098.52
    res_company_l10n_bd_corporate_tax_liability_fkey: 8176.24
    res_company_l10n_ch_delegate_country_id_fkey: 0.864
    res_company_l10n_cl_factoring_counterpart_account_id_fkey: 10872.3
    res_company_l10n_ec_tax_base_purchase_account_id_fkey: 10358.2
    res_company_l10n_ec_tax_base_sale_account_id_fkey: 10547
    res_company_l10n_ee_rounding_difference_loss_account_id_fkey: 8158.92
    res_company_l10n_ee_rounding_difference_profit_account_id_fkey: 7896.55
    res_company_l10n_eg_annual_leave_type_id_fkey: 0.887
    res_company_l10n_fr_rounding_difference_loss_account_id_fkey: 8227.23
    res_company_l10n_fr_rounding_difference_profit_account_id_fkey: 7965.89
    res_company_l10n_in_withholding_account_id_fkey: 7820.82
    res_company_l10n_nl_rounding_difference_loss_account_id_fkey: 7982.45
    res_company_l10n_nl_rounding_difference_profit_account_id_fkey: 7874.47
    res_company_leave_timesheet_task_id_fkey: 1.153
    res_company_loss_account_id_fkey: 12688.6
    res_company_nomenclature_id_fkey: 0.828
    res_company_paperformat_id_fkey: 0.941
    res_company_partner_id_fkey: 5.739
    res_company_project_time_mode_id_fkey: 1.273
    res_company_recruitment_folder_id_fkey: 0.816
    res_company_rental_loc_id_fkey: 0.851
    res_company_resource_calendar_id_fkey: 1.515
    res_company_revenue_accrual_account_id_fkey: 5175.54
    res_company_stock_mail_confirmation_template_id_fkey: 0.9
    res_company_stock_sms_confirmation_template_id_fkey: 0.861
    res_company_timesheet_encode_uom_id_fkey: 0.78
    res_company_transfer_account_id_fkey: 7072.12
    res_company_withholding_tax_base_account_id_fkey: 8502.05
    res_company_write_uid_fkey: 0.743
    soda_account_mapping_account_id_fkey: 398.04
    stock_landed_cost_lines_account_id_fkey: 658.493
    stock_location_valuation_in_account_id_fkey: 3940.27
    stock_location_valuation_out_account_id_fkey: 2818.23
    stock_valuation_layer_revaluation_account_id_fkey: 340.648

for a total of 661283ms = 11mn[^0].

This commit adds temporary indexes for every m2o field to account which is not already indexed[^1][^2] after all the l10n modules are installed, those indexes are then deleted at the end of the test to avoid polluting the database for the split tests.

This removes most of the cost of deleting accounts (not going to bother with the detail, the entire thing comes out at under a second), at a very minor cost (a few seconds) to create the indices though an increased overall load (due to having to update indexes).

Saves around 5mn on an unloaded 30mn build, and because it avoids a significant amount of parallelized seq scans it saves even more when running on a loaded runbot where parallel postgres workers are CPU starved (10~15mn out of 50~55).

Note: patched `load_file` because `l10n_tr` enables `tr_TR`, and then the tx subsystem complains about pretty much every module being installed because few to none of them have a tr_TR po file.

Backport of #217690

[^0]: `EXPLAIN ANALYZE`-ing everything slows down the test by a factor
    of 2x, which is why this takes 11mn instead of the original 5, and
    the test itself takes 1h instead of the original 30mn
[^1]: Kinda, currently it just checks if the field is `index` on the
    Odoo side, so it's going to miss things like manual partial
    indexes, or compound index (though in that case we should only
    take in account cases where the account field is the first one),
    etc...
[^2]: The specific missing indexes could have been enumerated and
    created specifically but it doesn't seem worth the hassle, the
    gain from trimming down the list would only be a fraction of a
    second from creating a few less indexes, with the risk of missing
    new missing indexes. A blacklist might make sense to avoid
    creating indexes for constraints with extremely low costs (either
    empty tables or already indexed) e.g. constraints with under 250ms
    total runtime[^3].
[^3]: Note that the numbers above are full dumps of the trigger times,
    a fair number of triggers in the dumps are *not* on accounts but
    are due to ancillary deletions or deletion cascades. Pretty much
    every trigger below triple digit (ms) runtime is a non-account
    trigger, and this PR is not creating indexes for any of those.