Update phpunit/phpunit requirement from ^10.5 to ^11.5

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/11.5.0/ChangeLog-11.5.md)
- [Commits](sebastianbergmann/phpunit@10.5.0...11.5.0)

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

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

composer.json

@@ -20,7 +20,7 @@
         "symfony/http-kernel": "^5.4 || ^6.4 || ^7.0"
     },
     "require-dev": {
-        "phpunit/phpunit": "^10.5",
+        "phpunit/phpunit": "^11.5",
         "spiriitlabs/form-filter-bundle": "^11.0"
     },
     "suggest": {