Update rubocop-rspec requirement from ~> 2.28.0 to ~> 2.29.1 (#200)

Updates the requirements on [rubocop-rspec](https://github.com/rubocop/rubocop-rspec) to permit the latest version.
- [Release notes](https://github.com/rubocop/rubocop-rspec/releases)
- [Changelog](https://github.com/rubocop/rubocop-rspec/blob/master/CHANGELOG.md)
- [Commits](rubocop/rubocop-rspec@v2.28.0...v2.29.1)

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

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

Gemfile

@@ -10,5 +10,5 @@ group :development do
   gem 'rubocop', '~> 1.62.0'
   gem 'rubocop-performance', '~> 1.21.0'
   gem 'rubocop-rake', '~> 0.6.0'
-  gem 'rubocop-rspec', '~> 2.28.0'
+  gem 'rubocop-rspec', '~> 2.29.1'
 end