A user without Time Off rights is now allowed to cancel their own
validated time off when:
- It's not yet started;
- No work-entries has been generated for it yet.
The time off is archived and the days taken reallocated.
closes odoo/odoo#76722
Taskid: 2643713
Related: odoo/upgrade#2843
Signed-off-by: Yannick Tivisse (yti) <yti@odoo.com>