Add type on getContainerExtension for future compat

User Deprecated: Method "Symfony\Component\HttpKernel\Bundle\Bundle::getContainerExtension()" might add "?ExtensionInterface" as a native return type declaration in the future. Do the same in child class "Overblog\GraphQLBundle\OverblogGraphQLBundle" now to avoid errors or add an explicit @return annotation to suppress this message.

Author: GromNaN

src/OverblogGraphQLBundle.php

@@ -52,7 +52,7 @@ public function build(ContainerBuilder $container): void
         $container->addCompilerPass(new ResolverTaggedServiceMappingPass(), PassConfig::TYPE_BEFORE_REMOVING);
     }
 
-    public function getContainerExtension()
+    public function getContainerExtension(): ?ExtensionInterface
     {
         if (!$this->extension instanceof ExtensionInterface) {
             $this->extension = new OverblogGraphQLExtension();