fix: Notification crash in before-quit (#21719)

shell/browser/api/atom_api_notification.cc

@@ -189,6 +189,7 @@ void Notification::NotificationClosed() {
 void Notification::Close() {
   if (notification_) {
     notification_->Dismiss();
+    notification_->set_delegate(nullptr);
     notification_.reset();
   }
 }