Update voxpupuli-rubocop requirement from ~> 3.0.0 to ~> 4.0.0

Updates the requirements on [voxpupuli-rubocop](https://github.com/voxpupuli/voxpupuli-rubocop) to permit the latest version.
- [Changelog](https://github.com/voxpupuli/voxpupuli-rubocop/blob/master/CHANGELOG.md)
- [Commits](voxpupuli/voxpupuli-rubocop@v3.0.0...v4.0.0)

---
updated-dependencies:
- dependency-name: voxpupuli-rubocop
  dependency-version: 4.0.0
  dependency-type: direct:development
...

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

Author: dependabot[bot]

puppet-modulebuilder.gemspec

@@ -27,7 +27,7 @@ Gem::Specification.new do |spec|
   spec.add_dependency 'minitar', '>= 0.9', '< 2'
   spec.add_dependency 'pathspec', '>= 0.2.1', '< 3.0.0'
 
-  spec.add_development_dependency 'voxpupuli-rubocop', '~> 3.0.0'
+  spec.add_development_dependency 'voxpupuli-rubocop', '~> 4.0.0'
 
   spec.required_ruby_version = Gem::Requirement.new('>= 3.1.0')
 end