Bump phpunit/phpunit from 9.6.7 to 11.4.3

Bumps [phpunit/phpunit](https://github.com/sebastianbergmann/phpunit) from 9.6.7 to 11.4.3.
- [Release notes](https://github.com/sebastianbergmann/phpunit/releases)
- [Changelog](https://github.com/sebastianbergmann/phpunit/blob/11.4.3/ChangeLog-11.4.md)
- [Commits](sebastianbergmann/phpunit@9.6.7...11.4.3)

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

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

composer.json

@@ -7,7 +7,7 @@
         "composer/installers": "^2.0.0"
     },
     "require-dev": {
-        "phpunit/phpunit": "^9.6",
+        "phpunit/phpunit": "^11.4",
         "wp-coding-standards/wpcs": "^2.3",
         "dealerdirect/phpcodesniffer-composer-installer": "^1.0.0",
         "phpcompatibility/phpcompatibility-wp": "^2.1.0",