chore(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/12.3.7/ChangeLog-12.3.md)
- [Commits](sebastianbergmann/phpunit@12.3.6...12.3.7)

---
updated-dependencies:
- dependency-name: phpunit/phpunit
  dependency-version: 12.3.7
  dependency-type: direct:development
...

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

Author: dependabot[bot]

composer.json

@@ -16,7 +16,7 @@
     },
     "require-dev": {
         "phpstan/phpstan": "2.1.22",
-        "phpunit/phpunit": "12.3.6",
+        "phpunit/phpunit": "12.3.7",
         "friendsofphp/php-cs-fixer": "3.85.1"
     },
     "autoload": {