Merge branch '5.3' into 5.4

* 5.3:
  [Runtime] Consider also $_ENV when resolving APP_RUNTIME and APP_RUNTIME_OPTIONS
  [Config] Fix signature generation with nested attributes on PHP 8.1
  [Cache] allow/provide psr/simple-cache v2
  [Validator] Add missing translations for Slovenian (sl)
  Add missing translations for Bosnian (bs)
  Bump Symfony version to 4.4.34
  Update VERSION for 4.4.33
  Update CONTRIBUTORS for 4.4.33
  Update CHANGELOG for 4.4.33

Author: nicolas-grekas

Internal/autoload_runtime.template

@@ -18,8 +18,8 @@ if (!is_object($app)) {
     throw new TypeError(sprintf('Invalid return value: callable object expected, "%s" returned from "%s".', get_debug_type($app), $_SERVER['SCRIPT_FILENAME']));
 }
 
-$runtime = $_SERVER['APP_RUNTIME'] ?? %runtime_class%;
-$runtime = new $runtime(($_SERVER['APP_RUNTIME_OPTIONS'] ?? []) + %runtime_options%);
+$runtime = $_SERVER['APP_RUNTIME'] ?? $_ENV['APP_RUNTIME'] ?? %runtime_class%;
+$runtime = new $runtime(($_SERVER['APP_RUNTIME_OPTIONS'] ?? $_ENV['APP_RUNTIME_OPTIONS'] ?? []) + %runtime_options%);
 
 [$app, $args] = $runtime
     ->getResolver($app)