Update dependency phpunit/phpunit to v12

Author: renovate[bot]

composer.json

@@ -24,7 +24,7 @@
     },
     "require-dev": {
         "friendsofphp/php-cs-fixer": "3.88.0",
-        "phpunit/phpunit": "^9.5",
+        "phpunit/phpunit": "^12.0",
         "guzzlehttp/guzzle": "^7.0"
     },
     "autoload": {