Update rubocop requirement from 1.65.1 to 1.66.0 (#144)

Updates the requirements on [rubocop](https://github.com/rubocop/rubocop) to permit the latest version.
- [Release notes](https://github.com/rubocop/rubocop/releases)
- [Changelog](https://github.com/rubocop/rubocop/blob/master/CHANGELOG.md)
- [Commits](rubocop/rubocop@v1.65.1...v1.66.0)

---
updated-dependencies:
- dependency-name: rubocop
  dependency-type: direct:production
...

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

Gemfile

@@ -4,7 +4,7 @@ gemspec
 gem "minitest", "~> 5.0"
 gem "minitest-rg", "~> 5.3"
 gem "rake", "~> 13.0"
-gem "rubocop", "1.65.1"
+gem "rubocop", "1.66.0"
 gem "rubocop-minitest", "0.36.0"
 gem "rubocop-packaging", "0.5.2"
 gem "rubocop-rake", "0.6.0"