Update simplecov requirement from ~> 0.21.0 to ~> 0.22.0

Updates the requirements on [simplecov](https://github.com/simplecov-ruby/simplecov) to permit the latest version.
- [Release notes](https://github.com/simplecov-ruby/simplecov/releases)
- [Changelog](https://github.com/simplecov-ruby/simplecov/blob/main/CHANGELOG.md)
- [Commits](simplecov-ruby/simplecov@v0.21.0...v0.22.0)

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

Signed-off-by: dependabot[bot] <[email protected]>

Gemfile

@@ -34,7 +34,7 @@ group :development do
   gem "rubocop-rspec", '= 2.19.0',               require: false
   gem "puppet-strings", '~> 4.0',                require: false
   gem "rb-readline", '= 0.5.5',                  require: false, platforms: [:mswin, :mingw, :x64_mingw]
-  gem 'simplecov', '~> 0.21.0',                  require: false
+  gem 'simplecov', '~> 0.22.0',                  require: false
   gem 'simplecov-console', '~> 0.9.0',           require: false
 end
 group :system_tests do