Add option for PHPUnit 12

Author: olivervogel

composer.json

@@ -18,7 +18,7 @@
         "php": "^8.2"
     },
     "require-dev": {
-        "phpunit/phpunit": "^10.0 || ^11.0",
+        "phpunit/phpunit": "^10.0 || ^11.0 || ^12.0",
         "phpstan/phpstan": "^2.1",
         "squizlabs/php_codesniffer": "^3.8",
         "slevomat/coding-standard": "~8.0"