chore(deps-dev): update phpunit/phpunit requirement || ^12.0

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/12.5.4/ChangeLog-12.5.md)
- [Commits](sebastianbergmann/phpunit@11.0.0...12.5.4)

---
updated-dependencies:
- dependency-name: phpunit/phpunit
  dependency-version: 12.5.4
  dependency-type: direct:development
...

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

Author: dependabot[bot]

composer.json

@@ -28,7 +28,7 @@
     }
   },
   "require-dev": {
-    "phpunit/phpunit": "^11.0",
+    "phpunit/phpunit": "^11.0 || ^12.0",
     "phpstan/phpstan": "^2.1",
     "phpstan/phpstan-phpunit": "^2.0",
     "squizlabs/php_codesniffer": "^4.0"