Update dependency phpunit/phpunit to v12

| datasource | package         | from   | to     |
| ---------- | --------------- | ------ | ------ |
| packagist  | phpunit/phpunit | 11.5.6 | 12.0.2 |

Author: renovate[bot]

composer.json

@@ -27,7 +27,7 @@
         "infection/infection": "^0.29.10",
         "laminas/laminas-diactoros": "^3.5.0",
         "php-http/curl-client": "^2.3.3",
-        "phpunit/phpunit": "^11.5.4",
+        "phpunit/phpunit": "^12.0.0",
         "psalm/plugin-phpunit": "^0.19.2",
         "react/child-process": "^0.6.6",
         "react/http": "^1.11",