Merge branch '6.4' into 7.0

* 6.4:
  not registered definitions must not be modified
  fix low deps
  [String] Fix Inflector for 'hardware'
  [Mime] Use streams instead of loading raw message generator into memory
  Bump Symfony version to 6.4.9
  Update VERSION for 6.4.8
  Update CHANGELOG for 6.4.8
  Bump Symfony version to 5.4.41
  Update VERSION for 5.4.40
  Update CONTRIBUTORS for 5.4.40
  Update CHANGELOG for 5.4.40

DependencyInjection/FrameworkExtension.php

@@ -1912,6 +1912,10 @@ private function registerSerializerConfiguration(array $config, ContainerBuilder
             $container->setParameter('serializer.default_context', $defaultContext);
         }
 
+        if (!$container->hasDefinition('serializer.normalizer.object')) {
+            return;
+        }
+
         $arguments = $container->getDefinition('serializer.normalizer.object')->getArguments();
         $context = [];