Update phpunit/phpunit requirement from ^9.3 to ^11.2

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/11.2.6/ChangeLog-11.2.md)
- [Commits](sebastianbergmann/phpunit@9.3.0...11.2.6)

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

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

composer.json

@@ -21,7 +21,7 @@
   },
   "require-dev": {
     "infection/infection": "*",
-    "phpunit/phpunit": "^9.3",
+    "phpunit/phpunit": "^11.2",
     "phpstan/phpstan": "*",
     "roave/security-advisories": "dev-master"
   },