This removes a leftover settings reference to the discontinued Gengo integration. It cleans up outdated configuration code for a module that was already removed, with no expected impact on current users.

All other references were removed in 481d1393e7bc72d6a163ecf7d7e265cf9e7d7b48 but this was left over "to be removed in master" (the commit landed in 14.1).

The actual module was removed in 14.0 (b38b72e456a) so this is quite overdue.

This change removes an unused reference in Belgian payroll accounting tests to a class that no longer exists. It helps keep internal test checks clean and prevents avoidable maintenance issues, with no expected impact on everyday users.

Cf odoo/odoo#98138

Had missed this (dead) import of one of the classes being removed.