[FIX] hr_holidays: overlap constraint

Allow to request a leave that create exactly when another leave start.

Closes #33665

opw-1998762

Signed-off-by: Nicolas Martinelli (nim) <nim@odoo.com>

addons/hr_holidays/models/hr_leave.py

@@ -425,7 +425,7 @@ class HolidaysRequest(models.Model):
     def _check_date(self):
         for holiday in self:
             domain = [
-                ('date_from', '<=', holiday.date_to),
+                ('date_from', '<', holiday.date_to),
                 ('date_to', '>', holiday.date_from),
                 ('employee_id', '=', holiday.employee_id.id),
                 ('id', '!=', holiday.id),