Update rubocop-minitest requirement from ~> 0.37.1 to ~> 0.38.0 (#129)

Updates the requirements on [rubocop-minitest](https://github.com/rubocop/rubocop-minitest) to permit the latest version.
- [Release notes](https://github.com/rubocop/rubocop-minitest/releases)
- [Changelog](https://github.com/rubocop/rubocop-minitest/blob/master/CHANGELOG.md)
- [Commits](rubocop/rubocop-minitest@v0.37.1...v0.38.0)

---
updated-dependencies:
- dependency-name: rubocop-minitest
  dependency-type: direct:development
...

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

Author: dependabot[bot]

Gemfile

@@ -9,7 +9,7 @@ group :development do
   gem 'minitest-around', '~> 0.5.0'
   gem 'rake', '>= 10.0.0'
   gem 'rubocop', '~> 1.75.0'
-  gem 'rubocop-minitest', '~> 0.37.1'
+  gem 'rubocop-minitest', '~> 0.38.0'
   gem 'rubocop-performance', '~> 1.24.0'
   gem 'rubocop-rake', '~> 0.7.1'
 end