[FIX] project: prevent archived assignees from not being visible

Prior to this fix:

    - Archived users are no more shown in the assignees

After this commit:

    - All users, including archived ones will be shown in the assignees.

task-2703358

closes odoo/odoo#80677

Related: odoo/enterprise#22641
Signed-off-by: Xavier <xbo@odoo.com>