feature: support symfony/config 7.x (#1120)

Author: deguif

composer.json

@@ -27,7 +27,7 @@
         "php": "^7.4 || ^8.0",
         "symfony/form": "^3.0 || ^4.0 || ^5.0 || ^6.0",
         "symfony/dependency-injection": "^3.0 || ^4.0 || ^5.0 || ^6.0",
-        "symfony/config": "^3.0 || ^4.0 || ^5.0 || ^6.0",
+        "symfony/config": "^3.0 || ^4.0 || ^5.0 || ^6.0 || ^7.0",
         "symfony/http-foundation": "^3.0 || ^4.0 || ^5.0 || ^6.0 || ^7.0",
         "symfony/http-kernel": "^3.0 || ^4.0 || ^5.0 || ^6.0 || ^7.0",
         "symfony/options-resolver": "^3.0 || ^4.0 || ^5.0 || ^6.0",