Convert patch to MR.

Closes #2918231

core/lib/Drupal/Core/Entity/EntityCreateAccessCheck.php

@@ -53,6 +53,18 @@ public function __construct(EntityTypeManagerInterface $entity_type_manager) {
   public function access(Route $route, RouteMatchInterface $route_match, AccountInterface $account) {
     [$entity_type, $bundle] = explode(':', $route->getRequirement($this->requirementsKey) . ':');
 
+    // For an entity type that has bundles, the $bundle must be specified.
+    $entity_type_definition = $this->entityTypeManager->getDefinition($entity_type);
+    if (empty($bundle) && $entity_type_definition && $entity_type_definition->hasKey('bundle')) {
+      @trigger_error(
+        sprintf(
+          'Defining a \'%s\' route requirement without a bundle for an entity type which has bundles (%s) is deprecated in drupal:11.2.0 and will be disallowed in drupal:12.0.0. Specify a bundle, either as a string or as a route parameter placeholder, in the route requirement. See https://www.drupal.org/node/3505093',
+          $this->requirementsKey,
+          $entity_type,
+        ), E_USER_DEPRECATED
+      );
+    }
+
     // The bundle argument can contain request argument placeholders like
     // {name}, loop over the raw variables and attempt to replace them in the
     // bundle name. If a placeholder does not exist, it won't get replaced.