[php] Bump required version of the php-cs-fixer (#232)

This supports versions of PHP in our matrix.

https://github.com/PHP-CS-Fixer/PHP-CS-Fixer/releases/tag/v3.51.0

Author: olleolleolle

php/composer.json

@@ -20,7 +20,7 @@
     "require-dev": {
         "phpunit/phpunit": "^10.0",
         "vimeo/psalm": "5.19.1",
-        "friendsofphp/php-cs-fixer": "^3.5",
+        "friendsofphp/php-cs-fixer": "^3.51",
         "psalm/plugin-phpunit": "^0.18.0",
         "nikic/php-parser": "^4.14"
     },