Update parallel_tests requirement from ~> 4.7.1 to ~> 4.9.0 (#136)

Updates the requirements on [parallel_tests](https://github.com/grosser/parallel_tests) to permit the latest version.

Updates `parallel_tests` from 4.7.2 to 4.9.0
- [Changelog](https://github.com/grosser/parallel_tests/blob/master/CHANGELOG.md)
- [Commits](grosser/parallel_tests@v4.7.2...v4.9.0)

---
updated-dependencies:
- dependency-name: parallel_tests
  dependency-type: direct:development
  update-type: version-update:semver-minor
  dependency-group: minor-and-patch-version-updates
...

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

Gemfile.lock

@@ -24,7 +24,7 @@ GEM
     minitest (5.25.4)
     netrc (0.11.0)
     parallel (1.26.3)
-    parallel_tests (4.7.2)
+    parallel_tests (4.9.0)
       parallel
     public_suffix (6.0.1)
     rake (13.2.1)
@@ -45,7 +45,7 @@ PLATFORMS
 DEPENDENCIES
   bundler (~> 2.2)
   minitest (~> 5.0)
-  parallel_tests (~> 4.7.1)
+  parallel_tests (~> 4.9.0)
   rake (~> 13.0)
   seatsio!
   webmock (~> 3.4, >= 3.4.2)

seatsio.gemspec

@@ -26,5 +26,5 @@ Gem::Specification.new do |spec|
   spec.add_development_dependency "rake", "~> 13.0"
   spec.add_development_dependency "minitest", "~> 5.0"
   spec.add_development_dependency 'webmock', '~> 3.4', '>= 3.4.2'
-  spec.add_development_dependency 'parallel_tests', '~> 4.7.1'
+  spec.add_development_dependency 'parallel_tests', '~> 4.9.0'
 end