This update simplifies the process of creating bank accounts within Odoo. Previously, bank account creation was fragmented; this change consolidates the process, making it more efficient for users and reducing potential errors. This improvement ensures consistent and accurate bank account management across the system.

Forward-Port-Of: odoo/odoo#249983

This update reduces the cost of running tests by consolidating setup steps and suppressing unnecessary logging. Specifically, expensive password creation and email logging within tests have been addressed, leading to faster test execution times and improved system performance.

- move a bunch of expensive setUp to setUpClass
- backport #152378 to avoid password keying in 17.0 also

This update streamlines the process of setting up tests for Odoo's payroll and timesheet modules. By centralizing test setup within classes, the team has improved the efficiency and reliability of automated testing. This change reduces the time spent on repetitive tasks and ensures more consistent test results.

This update optimizes how Odoo handles locale data, reducing unnecessary file system access. Previously, Odoo created many locale objects without actually using their data, leading to performance issues. This change adds a caching mechanism to prevent redundant checks, improving overall system speed and efficiency.

`babel.Locale.parse` checks if a locale is valid by calling `os.path.exists` on the resolved filename for the locale (this is done in `babel.localedata.exists`).

Babel does have a locale cache which it checks, but currently that cache is only populated when the locale is actually loaded[^1], therefore in cases where we instantiate a significant number of locales but never actually need to load locale data (e.g. formatting a significant number of datetimes, in qweb, using only non-localised patterns) this results in severe FS traffic for no reason.

[^1]: python-babel/babel#1254 has been submitted to fix this issue