Bump symfony 7.0 (#12)

Author: baiiko

composer.json

@@ -18,7 +18,7 @@
   "require": {
     "php": ">=8.0.2",
     "twig/twig": "^2.12|^3.0",
-    "symfony/config": "^5.0|^6.0"
+    "symfony/config": "^5.0|^6.0|^7.0"
   },
   "require-dev": {
     "phpunit/phpunit": "~3.7"