Maintenance: Bump rubocop-rails from 2.13.0 to 2.13.1
Bumps [rubocop-rails](https://github.com/rubocop/rubocop-rails) from 2.13.0 to 2.13.1.
- [Release notes](https://github.com/rubocop/rubocop-rails/releases)
- [Changelog](https://github.com/rubocop/rubocop-rails/blob/master/CHANGELOG.md)
- [Commits](https://github.com/rubocop/rubocop-rails/compare/v2.13.0...v2.13.1)