Update dependency phpunit/phpunit to v12

| datasource | package         | from   | to     |
| ---------- | --------------- | ------ | ------ |
| packagist  | phpunit/phpunit | 10.5.7 | 12.0.1 |


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

Author: renovate[bot]

composer.json

@@ -33,7 +33,7 @@
         "ergebnis/composer-normalize": "^2.41.1",
         "laminas/laminas-diactoros": "^3.3.0",
         "php-http/curl-client": "^2.3.1",
-        "phpunit/phpunit": "^10.5.5",
+        "phpunit/phpunit": "^12.0.0",
         "psalm/plugin-phpunit": "^0.19.0",
         "react/child-process": "^0.6.5",
         "react/http": "^1.9",