Bump phpunit/phpunit from 11.5.15 to 12.1.0

Bumps [phpunit/phpunit](https://github.com/sebastianbergmann/phpunit) from 11.5.15 to 12.1.0.
- [Release notes](https://github.com/sebastianbergmann/phpunit/releases)
- [Changelog](https://github.com/sebastianbergmann/phpunit/blob/12.1.0/ChangeLog-12.1.md)
- [Commits](https://github.com/sebastianbergmann/phpunit/compare/11.5.15...12.1.0)

---
updated-dependencies:
- dependency-name: phpunit/phpunit
  dependency-version: 12.1.0
  dependency-type: direct:development
  update-type: version-update:semver-major
...

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

composer.json

@@ -99,7 +99,7 @@
         "phpstan/phpstan": "^2",
         "phpstan/phpstan-deprecation-rules": "^2",
         "phpstan/phpstan-strict-rules": "^2",
-        "phpunit/phpunit": "^11"
+        "phpunit/phpunit": "^12"
     },
     "config": {
         "optimize-autoloader": true,