chore(deps): update rubocop requirement from ~> 1.59.0 to ~> 1.60.0

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@v1.59.0...v1.60.0)

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

Signed-off-by: dependabot[bot] <support@github.com>

Gemfile

@@ -7,5 +7,5 @@
 source 'https://rubygems.org'
 
 gem 'rake', '~> 13.0'
-gem 'rubocop', '~> 1.59.0'
+gem 'rubocop', '~> 1.60.0'
 gem 'rubocop-performance', '~> 1.20.2'