[FIX] hr_holidays: Fix the wrong behavior of no-validation leave type

Currently when you create time off type with no validation and then
create new time off request, save and status is approved.
However, if you refuse the time off and reset to Draft and confirm it
then status will be 'To approve' when it should be 'Approved'.

So after this commit, on confirm of refused time off with validation
type 'no validation' automatically move to the 'Approved' instead of
'To Approve'.

closes odoo/odoo#48087

Taskid: 2206222
Closes: #47738
X-original-commit: 3d2391d350ea7ed572cf6818ab3f607c99fe0bf5
Signed-off-by: Yannick Tivisse (yti) <yti@odoo.com>

addons/hr_holidays/models/hr_leave.py

@@ -891,6 +891,10 @@ class HolidaysRequest(models.Model):
         if self.filtered(lambda holiday: holiday.state != 'draft'):
             raise UserError(_('Time off request must be in Draft state ("To Submit") in order to confirm it.'))
         self.write({'state': 'confirm'})
+        holidays = self.filtered(lambda leave: leave.validation_type == 'no_validation')
+        if holidays:
+            # Automatic validation should be done in sudo, because user might not have the rights to do it by himself
+            holidays.sudo().action_validate()
         self.activity_update()
         return True