Update chefstyle requirement from 1.7.5 to 2.1.1

Updates the requirements on [chefstyle](https://github.com/chef/chefstyle) to permit the latest version.
- [Release notes](https://github.com/chef/chefstyle/releases)
- [Changelog](https://github.com/chef/chefstyle/blob/main/CHANGELOG.md)
- [Commits](chef/chefstyle@v1.7.5...v2.1.1)

---
updated-dependencies:
- dependency-name: chefstyle
  dependency-type: direct:development
...

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

Gemfile

@@ -22,5 +22,5 @@ group :test do
   gem "rspec-mocks"
   gem "rspec_junit_formatter"
   gem "fog-core"
-  gem "chefstyle", "1.7.5"
+  gem "chefstyle", "2.1.1"
 end