Update dependency phpunit/phpunit to v12

| datasource | package         | from    | to     |
| ---------- | --------------- | ------- | ------ |
| packagist  | phpunit/phpunit | 11.5.48 | 12.5.6 |

Author: renovate[bot]

composer.json

@@ -33,7 +33,7 @@
     ],
     "require-dev": {
         "phpbench/phpbench": "^1.4.3",
-        "phpunit/phpunit": "^11.5.48"
+        "phpunit/phpunit": "^12.5.6"
     },
     "autoload": {
         "psr-4": {