Update rubocop requirement from = 1.42.0 to = 1.86.0

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@v1.42.0...v1.86.0)

---
updated-dependencies:
- dependency-name: rubocop
  dependency-version: 1.86.0
  dependency-type: direct:development
...

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

Author: dependabot[bot]

fastlane-plugin-mint.gemspec

@@ -23,7 +23,7 @@ Gem::Specification.new do |spec|
   spec.add_development_dependency('rake')
   spec.add_development_dependency('rspec')
   spec.add_development_dependency('rspec_junit_formatter')
-  spec.add_development_dependency('rubocop', '1.42.0')
+  spec.add_development_dependency('rubocop', '1.86.0')
   spec.add_development_dependency('rubocop-performance')
   spec.add_development_dependency('rubocop-require_tools')
   spec.add_development_dependency('simplecov')