Update rubocop requirement from ~> 0.84.0 to ~> 0.85.0

Updates the requirements on [rubocop](https://github.com/rubocop-hq/rubocop) to permit the latest version.
- [Release notes](https://github.com/rubocop-hq/rubocop/releases)
- [Changelog](https://github.com/rubocop-hq/rubocop/blob/master/CHANGELOG.md)
- [Commits](rubocop/rubocop@v0.84.0...v0.85.0)

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

client_side_validations.gemspec

@@ -36,7 +36,7 @@ Gem::Specification.new do |spec|
   spec.add_development_dependency 'minitest', '~> 5.14'
   spec.add_development_dependency 'mocha', '~> 1.11'
   spec.add_development_dependency 'rake', '~> 13.0'
-  spec.add_development_dependency 'rubocop', '~> 0.84.0'
+  spec.add_development_dependency 'rubocop', '~> 0.85.0'
   spec.add_development_dependency 'rubocop-performance', '~> 1.5'
   spec.add_development_dependency 'rubocop-rails', '~> 2.5'
   spec.add_development_dependency 'simplecov', '~> 0.18.5'