Let bundler figure out dependencies

ruby gems have metadata on the minimum supported ruby version and
supported versions of other libs so it can very well discover
limitations by itself without us hand-holding it.

also, imposing an upper bound on versions is an anti-pattern IMHO so
let's just stop that. if something breaks for real when new versions are
released, then we can add an upper bound on version dependencies *for a
reason*.

Gemfile

@@ -10,16 +10,11 @@ group :tests do
  # Use info from metadata.json for tests
  gem 'puppetlabs_spec_helper', '>= 0.10.0'
  gem 'puppet-lint', '>= 2.3.0'
- # rubocop:disable Bundler/DuplicatedGem
- gem 'puppet_metadata', '~> 4.0', require: false if Gem::Version.new(RUBY_VERSION.dup) >= Gem::Version.new('2.7.0')
- gem 'puppet_metadata', '~> 2.1', require: false if Gem::Version.new(RUBY_VERSION.dup) < Gem::Version.new('2.7.0')
- # rubocop:enable Bundler/DuplicatedGem
+ gem 'puppet_metadata'
+ gem 'puppet_metadata'
  gem 'rspec-puppet', '>= 2.4.0'
  # This draws in rubocop and other useful gems for puppet tests
- # rubocop:disable Bundler/DuplicatedGem
- gem 'voxpupuli-test', '~> 7.0', require: false if Gem::Version.new(RUBY_VERSION.dup) >= Gem::Version.new('2.7.0')
- gem 'voxpupuli-test', '~> 5.7', require: false if Gem::Version.new(RUBY_VERSION.dup) < Gem::Version.new('2.7.0')
- # rubocop:enable Bundler/DuplicatedGem
+ gem 'voxpupuli-test'
 end
 
 group :docs do