Update phpunit/phpunit requirement from ^9.0 to ^11.4

Updates the requirements on [phpunit/phpunit](https://github.com/sebastianbergmann/phpunit) to permit the latest version.
- [Release notes](https://github.com/sebastianbergmann/phpunit/releases)
- [Changelog](https://github.com/sebastianbergmann/phpunit/blob/11.4.0/ChangeLog-11.4.md)
- [Commits](sebastianbergmann/phpunit@9.0.0...11.4.0)

---
updated-dependencies:
- dependency-name: phpunit/phpunit
  dependency-type: direct:development
...

Signed-off-by: dependabot[bot] <[email protected]>

composer.json

@@ -18,7 +18,7 @@
     },
     "require-dev": {
         "symfony/var-dumper": "^5.4",
-        "phpunit/phpunit": "^9.0",
+        "phpunit/phpunit": "^11.4",
         "friendsofphp/php-cs-fixer": "^3.11"
     },
     "autoload": {