build: bump parallel_tests from 2.29.2 to 2.30.0 in /Library/Homebrew

Bumps [parallel_tests](https://github.com/grosser/parallel_tests) from 2.29.2 to 2.30.0.
- [Release notes](https://github.com/grosser/parallel_tests/releases)
- [Commits](https://github.com/grosser/parallel_tests/compare/v2.29.2...v2.30.0

)

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