Add missing return types

This will avoid deprecation messages

src/Bundle/ChillPersonBundle/AccompanyingPeriod/Events/UserRefEventSubscriber.php

@@ -25,7 +25,7 @@ class UserRefEventSubscriber implements EventSubscriberInterface
 {
     public function __construct(private readonly Security $security, private readonly TranslatorInterface $translator, private readonly \Twig\Environment $engine, private readonly NotificationPersisterInterface $notificationPersister) {}
 
-    public static function getSubscribedEvents()
+    public static function getSubscribedEvents(): array
     {
         return [
             'workflow.accompanying_period_lifecycle.entered' => [