Draft: Issue #3433389: Drupal 11 compatibility

Closes #3433389

Includes the following changes:

• Changes made by project update bot
• Global route cache contexts are now added with an EventSubscriber to work around https://www.drupal.org/project/drupal/issues/3452181

src/EventSubscriber/NodeSubscriber.php

@@ -70,7 +70,7 @@ class NodeSubscriber implements EventSubscriberInterface {
   /**
    * {@inheritdoc}
    */
-  public static function getSubscribedEvents() {
+  public static function getSubscribedEvents(): array {
     $events[KernelEvents::REQUEST] = array('onRequest');
     return $events;
   }