build(deps-dev): bump phpunit/phpunit from 9.6.15 to 9.6.33

Bumps [phpunit/phpunit](https://github.com/sebastianbergmann/phpunit) from 9.6.15 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@9.6.15...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

@@ -15,7 +15,7 @@
         "squizlabs/php_codesniffer": "^3.10.3"
     },
     "require-dev": {
-        "phpunit/phpunit": "^9.6.15"
+        "phpunit/phpunit": "^9.6.33"
     },
     "autoload": {
         "psr-4": {