Update phpunit/phpunit requirement from ^10.3.2 to ^11.2.8

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/11.2.8/ChangeLog-11.2.md)
- [Commits](sebastianbergmann/phpunit@10.3.2...11.2.8)

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

Signed-off-by: dependabot[bot] <support@github.com>

composer.json

@@ -27,7 +27,7 @@
         "php": "^8.1"
     },
     "require-dev": {
-        "phpunit/phpunit": "^10.3.2"
+        "phpunit/phpunit": "^11.2.8"
     },
     "autoload": {
         "psr-4": {