Build(deps-dev): Bump parallel_tests from 4.2.0 to 4.2.1 (#21540)

Bumps [parallel_tests](https://github.com/grosser/parallel_tests) from 4.2.0 to 4.2.1.
- [Changelog](https://github.com/grosser/parallel_tests/blob/master/CHANGELOG.md)
- [Commits](https://github.com/grosser/parallel_tests/compare/v4.2.0...v4.2.1)

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

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Gemfile.lock

@@ -308,7 +308,7 @@ GEM
       openssl (> 2.0)
     optimist (3.0.1)
     parallel (1.23.0)
-    parallel_tests (4.2.0)
+    parallel_tests (4.2.1)
       parallel
     parser (3.2.2.1)
       ast (~> 2.4.1)