Update phpunit/phpunit requirement from ^11.5.2 to ^11.5.4 (#131)

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/11.5.4/ChangeLog-11.5.md)
- [Commits](sebastianbergmann/phpunit@11.5.2...11.5.4)

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

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Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

composer.json

@@ -28,7 +28,7 @@
   },
   "require-dev": {
     "php-cs-fixer/shim": "^3.67",
-    "phpunit/phpunit": "^11.5.2",
+    "phpunit/phpunit": "^11.5.4",
     "psalm/phar": "^5.26"
   },
   "autoload": {