Merge branch '5.4' into 6.0

* 5.4:
  [DependencyInjection] remove static cache from `ServiceSubscriberTrait`

Author: derrabus

src/Symfony/Contracts/Service/ServiceSubscriberTrait.php

@@ -30,12 +30,6 @@ trait ServiceSubscriberTrait
      */
     public static function getSubscribedServices(): array
     {
-        static $services;
-
-        if (null !== $services) {
-            return $services;
-        }
-
         $services = method_exists(get_parent_class(self::class) ?: '', __FUNCTION__) ? parent::getSubscribedServices() : [];
 
         foreach ((new \ReflectionClass(self::class))->getMethods() as $method) {