Update rubocop requirement from ~> 0.92.0 to ~> 1.20.0 (#2154)

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](https://github.com/rubocop/rubocop/compare/v0.92.0...v1.20.0)

---
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

@@ -24,7 +24,7 @@ gem 'nokogiri', '>= 1.11.1'
 gem 'rake', '>= 12.3.3'
 gem 'otr-activerecord', '>= 1.4.2'
 gem 'sqlite3'
-gem 'rubocop', '~> 0.92.0', require: false
+gem 'rubocop', '~> 1.20.0', require: false
 
 # Geolocation support
 group :geoip do