Bump phpunit/phpunit from 12.1.6 to 12.2.1

Bumps [phpunit/phpunit](https://github.com/sebastianbergmann/phpunit) from 12.1.6 to 12.2.1.
- [Release notes](https://github.com/sebastianbergmann/phpunit/releases)
- [Changelog](https://github.com/sebastianbergmann/phpunit/blob/12.2.1/ChangeLog-12.2.md)
- [Commits](sebastianbergmann/phpunit@12.1.6...12.2.1)

---
updated-dependencies:
- dependency-name: phpunit/phpunit
  dependency-version: 12.2.1
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

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Author: dependabot[bot]