build(deps-dev): update phpunit/phpunit requirement (#34)

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/10.5.13/ChangeLog-10.5.md)
- [Commits](sebastianbergmann/phpunit@10.5.12...10.5.13)

---
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>

composer.json

@@ -27,7 +27,7 @@
     },
     "require-dev": {
         "friendsofphp/php-cs-fixer": "3.51.0",
-        "phpunit/phpunit": "10.5.12",
+        "phpunit/phpunit": "10.5.13",
         "rector/rector": "1.0.2",
         "symplify/rule-doc-generator": "12.1.1"
     },