build(deps-dev): bump phpunit/phpunit from 8.5.37 to 8.5.38

Bumps [phpunit/phpunit](https://github.com/sebastianbergmann/phpunit) from 8.5.37 to 8.5.38.
- [Release notes](https://github.com/sebastianbergmann/phpunit/releases)
- [Changelog](https://github.com/sebastianbergmann/phpunit/blob/8.5.38/ChangeLog-8.5.md)
- [Commits](sebastianbergmann/phpunit@8.5.37...8.5.38)

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

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