Bump rubocop from 1.24.0 to 1.25.0 (#2270)

Bumps [rubocop](https://github.com/rubocop/rubocop) from 1.24.0 to 1.25.0.
- [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/v1.24.0...v1.25.0)

---
updated-dependencies:
- dependency-name: rubocop
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

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

Gemfile

@@ -23,7 +23,7 @@ gem 'espeak-ruby', '>= 1.0.4' # Text-to-Voice
 gem 'rake', '>= 12.3.3'
 gem 'otr-activerecord', '>= 1.4.2'
 gem 'sqlite3'
-gem 'rubocop', '~> 1.24.0', require: false
+gem 'rubocop', '~> 1.25.0', require: false
 
 # Geolocation support
 group :geoip do