build(deps-dev): bump phpunit/phpunit from 9.6.19 to 12.3.0

Bumps [phpunit/phpunit](https://github.com/sebastianbergmann/phpunit) from 9.6.19 to 12.3.0.
- [Release notes](https://github.com/sebastianbergmann/phpunit/releases)
- [Changelog](https://github.com/sebastianbergmann/phpunit/blob/12.3.0/ChangeLog-12.3.md)
- [Commits](sebastianbergmann/phpunit@9.6.19...12.3.0)

---
updated-dependencies:
- dependency-name: phpunit/phpunit
  dependency-version: 12.3.0
  dependency-type: direct:development
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

composer.json

@@ -33,7 +33,7 @@
         "mermaid-class-diagram"
     ],
     "require-dev": {
-        "phpunit/phpunit": "^9.5"
+        "phpunit/phpunit": "^9.5 || ^12.0"
     },
     "require": {
         "symfony/finder": "^7.0",