Update voxpupuli-rubocop requirement from ~> 3.0.0 to ~> 3.1.0

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...v3.1.0)

---
updated-dependencies:
- dependency-name: voxpupuli-rubocop
  dependency-version: 3.1.0
  dependency-type: direct:development
...

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

Author: dependabot[bot]

voxpupuli-puppet-lint-plugins.gemspec

@@ -34,5 +34,5 @@ Gem::Specification.new do |s|
   s.add_dependency 'puppet-lint-version_comparison-check', '~> 2.0'
 
   s.add_development_dependency 'rake', '~> 13.0', '>= 13.0.6'
-  s.add_development_dependency 'voxpupuli-rubocop', '~> 3.0.0'
+  s.add_development_dependency 'voxpupuli-rubocop', '~> 3.1.0'
 end