Update dependency phpunit/phpunit to v11 (#15)

| datasource | package         | from    | to     |
| ---------- | --------------- | ------- | ------ |
| packagist  | phpunit/phpunit | 10.5.11 | 11.0.3 |

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

Author: renovate[bot]

composer.json

@@ -14,7 +14,7 @@
         "php": "~8.2.0 || ~8.3.0"
     },
     "require-dev": {
-        "phpunit/phpunit": "^10.5.11",
+        "phpunit/phpunit": "^11.0.3",
         "slam/php-cs-fixer-extensions": "^3.10"
     },
     "autoload": {