[FIX] hr_holidays_attendance: grant back overtime on leave deletion

The linked overtime record was not deleted when deleting a time off.
Meaning that those hours were lost.

task-3097259

closes odoo/odoo#107713

Signed-off-by: Kevin Baptiste <kba@odoo.com>

addons/hr_holidays_attendance/models/hr_leave.py

@@ -100,3 +100,8 @@ class HRLeave(models.Model):
                     employee_dates[leave.employee_id].add(self.env['hr.attendance']._get_day_start_and_day(leave.employee_id, leave.date_from + timedelta(days=d)))
         if employee_dates:
             self.env['hr.attendance']._update_overtime(employee_dates)
+
+    def unlink(self):
+        # TODO master change to ondelete
+        self.sudo().overtime_id.unlink()
+        return super().unlink()

addons/hr_holidays_attendance/tests/test_holidays_overtime.py

@@ -134,6 +134,11 @@ class TestHolidaysOvertime(TransactionCase):
         self.assertTrue(leave.overtime_id.exists(), "Overtime should be created")
         self.assertEqual(self.employee.total_overtime, 0)
 
+        overtime = leave.overtime_id
+        leave.unlink()
+        self.assertFalse(overtime.exists(), "Overtime should be deleted along with the leave")
+        self.assertEqual(self.employee.total_overtime, 8)
+
     def test_leave_check_overtime_write(self):
         self.new_attendance(check_in=datetime(2021, 1, 2, 8), check_out=datetime(2021, 1, 2, 16))
         self.new_attendance(check_in=datetime(2021, 1, 3, 8), check_out=datetime(2021, 1, 3, 16))