Merge branch '6.4' into 7.3

* 6.4:
  register attribute loader arguments in a forward-compatible way
  mark test using a Redis connection as an integration test
  ensure compatibility with Relay extension 0.20.0
  [DependencyInjection] Fix `query_string` env processor for URLs without query string
  [DependencyInjection] Fix state corruption in PhpFileLoader during recursive imports
  [FrameworkBundle] Add missing `useAttributeAsKey` calls
  [DependencyInjection] Fix loose validation in #[Autowire] attribute
  [HttpClient] Fix releasing uploaded stream resources

Author: xabbuh

DependencyInjection/Configuration.php

@@ -1927,6 +1927,7 @@ private function addHttpClientSection(ArrayNodeDefinition $rootNode, callable $e
                                 ->end()
                                 ->arrayNode('vars')
                                     ->info('Associative array: the default vars used to expand the templated URI.')
+                                    ->useAttributeAsKey('name')
                                     ->normalizeKeys(false)
                                     ->variablePrototype()->end()
                                 ->end()
@@ -2007,6 +2008,7 @@ private function addHttpClientSection(ArrayNodeDefinition $rootNode, callable $e
                                 ->end()
                                 ->arrayNode('extra')
                                     ->info('Extra options for specific HTTP client.')
+                                    ->useAttributeAsKey('name')
                                     ->normalizeKeys(false)
                                     ->variablePrototype()->end()
                                 ->end()
@@ -2162,6 +2164,7 @@ private function addHttpClientSection(ArrayNodeDefinition $rootNode, callable $e
                                     ->end()
                                     ->arrayNode('extra')
                                         ->info('Extra options for specific HTTP client.')
+                                        ->useAttributeAsKey('name')
                                         ->normalizeKeys(false)
                                         ->variablePrototype()->end()
                                     ->end()