Fix some self deprecation notices

src/Event/Listener/AuthenticationFailureListener.php

@@ -18,7 +18,7 @@ class AuthenticationFailureListener implements EventSubscriberInterface
         $this->logger = $logger;
     }
 
-    public static function getSubscribedEvents()
+    public static function getSubscribedEvents(): array
     {
         return [
             AuthenticationEvents::AUTHENTICATION_FAILURE => 'onAuthenticationFailure',

src/Event/Listener/CreateConfigListener.php

@@ -38,7 +38,7 @@ class CreateConfigListener implements EventSubscriberInterface
         $this->displayThumbnails = $displayThumbnails;
     }
 
-    public static function getSubscribedEvents()
+    public static function getSubscribedEvents(): array
     {
         return [
             // when a user register using the normal form

src/Event/Listener/LocaleListener.php

@@ -34,7 +34,7 @@ class LocaleListener implements EventSubscriberInterface
         }
     }
 
-    public static function getSubscribedEvents()
+    public static function getSubscribedEvents(): array
     {
         return [
             // must be registered before the default Locale listener

src/Event/Listener/PasswordResettingListener.php

@@ -22,7 +22,7 @@ class PasswordResettingListener implements EventSubscriberInterface
         $this->router = $router;
     }
 
-    public static function getSubscribedEvents()
+    public static function getSubscribedEvents(): array
     {
         return [
             FOSUserEvents::RESETTING_RESET_SUCCESS => 'onPasswordResettingSuccess',

src/Event/Listener/RegistrationListener.php

@@ -26,7 +26,7 @@ class RegistrationListener implements EventSubscriberInterface
         $this->urlGenerator = $urlGenerator;
     }
 
-    public static function getSubscribedEvents()
+    public static function getSubscribedEvents(): array
     {
         return [
             FOSUserEvents::REGISTRATION_INITIALIZE => 'onRegistrationInitialize',

src/Event/Subscriber/DownloadImagesSubscriber.php

@@ -25,7 +25,7 @@ class DownloadImagesSubscriber implements EventSubscriberInterface
         $this->logger = $logger;
     }
 
-    public static function getSubscribedEvents()
+    public static function getSubscribedEvents(): array
     {
         return [
             EntrySavedEvent::NAME => 'onEntrySaved',

src/Event/Subscriber/GenerateCustomCSSSubscriber.php

@@ -18,7 +18,7 @@ class GenerateCustomCSSSubscriber implements EventSubscriberInterface
         $this->compiler = $compiler;
     }
 
-    public static function getSubscribedEvents()
+    public static function getSubscribedEvents(): array
     {
         return [
             ConfigUpdatedEvent::NAME => 'onConfigUpdated',

src/Event/Subscriber/SchemaAdapterSubscriber.php

@@ -15,7 +15,7 @@ class SchemaAdapterSubscriber implements EventSubscriber
         $this->databaseTablePrefix = $databaseTablePrefix;
     }
 
-    public function getSubscribedEvents()
+    public function getSubscribedEvents(): array
     {
         return ['postGenerateSchema'];
     }

src/Event/Subscriber/TablePrefixSubscriber.php

@@ -25,7 +25,7 @@ class TablePrefixSubscriber implements EventSubscriber
         $this->tablePrefix = (string) $tablePrefix;
     }
 
-    public function getSubscribedEvents()
+    public function getSubscribedEvents(): array
     {
         return ['loadClassMetadata'];
     }