This update streamlines test execution by consolidating repetitive setup steps into a single location, reducing the time and resources needed to run tests. By avoiding redundant object creation, the changes improve test performance and overall system stability. This primarily impacts the Google Calendar and Microsoft Calendar modules.

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

Forward-Port-Of: odoo/odoo#251045
Forward-Port-Of: odoo/odoo#250667

This update streamlines the process of setting up tests for several core Odoo modules, specifically within the timesheet and payroll areas. By centralizing test setup, the team has improved the efficiency and reliability of our automated testing, leading to faster identification and resolution of potential issues.

Forward-Port-Of: odoo/enterprise#108971
Forward-Port-Of: odoo/enterprise#108739