chore(deps-dev): bump phpunit/phpunit from 9.5.28 to 9.6.33

Bumps [phpunit/phpunit](https://github.com/sebastianbergmann/phpunit) from 9.5.28 to 9.6.33.
- [Release notes](https://github.com/sebastianbergmann/phpunit/releases)
- [Changelog](https://github.com/sebastianbergmann/phpunit/blob/9.6.33/ChangeLog-9.6.md)
- [Commits](sebastianbergmann/phpunit@9.5.28...9.6.33)

---
updated-dependencies:
- dependency-name: phpunit/phpunit
  dependency-version: 9.6.33
  dependency-type: direct:development
...

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

Author: dependabot[bot]

composer.json

@@ -62,7 +62,7 @@
     "require-dev": {
         "behat/behat": "3.8.1",
         "dealerdirect/phpcodesniffer-composer-installer": "0.7.0",
-        "phpunit/phpunit": "9.5.*",
+        "phpunit/phpunit": "9.6.*",
         "phpcompatibility/php-compatibility": "8.2.0",
         "wp-coding-standards/wpcs": "0.13.1"
     },