Resolve #3435710 "Automated drupal 11"

Closes #3435710

src/EventSubscriber/ExceptionSubscriberBase.php

@@ -149,7 +149,7 @@ abstract class ExceptionSubscriberBase implements EventSubscriberInterface {
   /**
    * {@inheritdoc}
    */
-  public static function getSubscribedEvents() {
+  public static function getSubscribedEvents(): array {
     $events[KernelEvents::EXCEPTION][] = ['onException', static::getPriority()];
     return $events;
   }