Bump phpunit/phpunit from 9.6.33 to 12.5.22

Bumps [phpunit/phpunit](https://github.com/sebastianbergmann/phpunit) from 9.6.33 to 12.5.22.
- [Release notes](https://github.com/sebastianbergmann/phpunit/releases)
- [Changelog](https://github.com/sebastianbergmann/phpunit/blob/12.5.22/ChangeLog-12.5.md)
- [Commits](sebastianbergmann/phpunit@9.6.33...12.5.22)

---
updated-dependencies:
- dependency-name: phpunit/phpunit
  dependency-version: 12.5.22
  dependency-type: direct:development
...

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

Author: dependabot[bot]

composer.json

@@ -17,7 +17,7 @@
         "php-http/discovery": "^1.20"
     },
     "require-dev": {
-        "phpunit/phpunit": "^9",
+        "phpunit/phpunit": "^9 || ^12",
         "phpstan/phpstan": "^2.1",
         "symfony/cache": "^6",
         "symfony/http-client": "^6",