Update dependency phpunit/phpunit to v11 (#20)

| 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>

composer.json

@@ -18,7 +18,7 @@
     "require-dev": {
         "phpstan/phpstan": "^1.10.59",
         "phpstan/phpstan-phpunit": "^1.3.16",
-        "phpunit/phpunit": "^10.5.11",
+        "phpunit/phpunit": "^11.0.3",
         "slam/php-cs-fixer-extensions": "^3.10",
         "slam/phpstan-extensions": "^6.2.0"
     },