manager: use dedicated method to deactivate user (#51112)

src/authentic2/manager/user_views.py

@@ -333,8 +333,7 @@ class UserDetailView(OtherActionsMixin, BaseDetailView):
             messages.warning(request, _('You cannot desactivate your own '
                              'user'))
         else:
-            self.object.is_active = False
-            self.object.save()
+            self.object.mark_as_inactive()
             request.journal.record('manager.user.deactivation', target_user=self.object)
 
     def action_password_reset(self, request, *args, **kwargs):