Update composer.json to allow Symfony 6.x

Author: Clement Herreman

composer.json

@@ -25,8 +25,8 @@
     },
     "require-dev": {
         "phpunit/phpunit": "^9.4.3",
-        "symfony/cache": "5.2.0",
-        "symfony/http-client": "^5.2",
+        "symfony/cache": "^5.2 || ^6.0",
+        "symfony/http-client": "^5.2 || ^6.0",
         "phpstan/phpstan": "^0.12.64"
     },
     "scripts": {