[TASK] Update phpunit/phpunit requirement from ^11.2.7 to ^11.2.8 (#91)

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/11.2.8/ChangeLog-11.2.md)
- [Commits](sebastianbergmann/phpunit@11.2.7...11.2.8)

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

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

composer.json

@@ -25,7 +25,7 @@
         "phpstan/phpstan-deprecation-rules": "^1.2",
         "phpstan/phpstan-phpunit": "^1.4.0",
         "phpstan/phpstan-strict-rules": "^1.6.0",
-        "phpunit/phpunit": "^11.2.7",
+        "phpunit/phpunit": "^11.2.8",
         "rector/rector": "^1.2.1",
         "spaze/phpstan-disallowed-calls": "^3.4",
         "squizlabs/php_codesniffer": "^3.10.1"