Temporarily pin symfony/http-foundation to < 6 to fix tests on PHP 8+

Author: clue

composer.json

@@ -35,6 +35,7 @@
       , "symfony/routing": "^2.6|^3.0|^4.0|^5.0|^6.0"
     }
   , "require-dev": {
-        "phpunit/phpunit": "^9.6 || ^5.7 || ^4.8.36"
+        "phpunit/phpunit": "^9.6 || ^5.7 || ^4.8.36",
+        "symfony/http-foundation": "^2.6|^3.0|^4.0|^5.0"
     }
 }