[IMP] hr_holidays: clean leave responsibles on user creation

New users automatically received the Leave Responsible role even though
they were not managing any employees.

closes odoo/odoo#78436

Taskid: 2635715
Signed-off-by: Kevin Baptiste <kba@odoo.com>

addons/hr_holidays/models/res_users.py

@@ -69,3 +69,9 @@ class User(models.Model):
         responsibles_to_remove_ids = set(self.ids) - {x['leave_manager_id'][0] for x in res}
         approver_group.sudo().write({
             'users': [(3, manager_id) for manager_id in responsibles_to_remove_ids]})
+
+    @api.model_create_multi
+    def create(self, vals_list):
+        users = super().create(vals_list)
+        users._clean_leave_responsible_users()
+        return users