Update phpunit/phpunit requirement from ^9.5.3 to ^11.4.0

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@9.5.3...11.4.0)

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

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

composer.json

@@ -15,7 +15,7 @@
         "ext-json": "*"
     },
     "require-dev": {
-        "phpunit/phpunit": "^9.5.3",
+        "phpunit/phpunit": "^11.4.0",
         "mockery/mockery": "^1.4.0"
     },
     "autoload": {