build(deps-dev): update phpunit/phpunit requirement

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/11.3.6/ChangeLog-11.3.md)
- [Commits](sebastianbergmann/phpunit@7.5.20...11.3.6)

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

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

composer.json

@@ -36,7 +36,7 @@
     },
     "require-dev": {
         "fakerphp/faker": "^v1.16.0",
-        "phpunit/phpunit": "^7.5.20",
+        "phpunit/phpunit": "^11.3.6",
         "psr/container": "~1.0.0"
     },
     "autoload": {