Update dependency phpunit/phpunit to v12 (#45)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

composer.json

@@ -36,7 +36,7 @@
         "roave/security-advisories": "dev-latest",
         "squizlabs/php_codesniffer": "^3.7",
         "phpmd/phpmd": "^2.14",
-        "phpunit/phpunit": "^10.0 || ^11.2",
+        "phpunit/phpunit": "^10.0 || ^11.2 || ^12.0",
         "phpstan/phpstan": "^1.10",
         "phpstan/phpstan-phpunit": "^1.3",
         "phpstan/phpstan-strict-rules": "^1.5",