build: relax Puppet version

Makes this gem easier to use, because you no longer need
to override ENV[PUPPET_VERSION] if you don't want Puppet 5.

octocatalog-diff.gemspec

@@ -1,10 +1,7 @@
 require 'json'
 
-DEFAULT_PUPPET_VERSION = '5.5.22'.freeze
-
 Gem::Specification.new do |s|
   s.required_ruby_version = '>= 2.6.0'
-  puppet_version = ENV['PUPPET_VERSION'] || DEFAULT_PUPPET_VERSION
 
   s.name        = 'octocatalog-diff'
   s.version     = ENV['OCTOCATALOG_DIFF_VERSION'] || File.read(File.join(File.dirname(__FILE__), '.version')).strip
@@ -30,23 +27,13 @@ EOF
   s.add_runtime_dependency 'hashdiff', '>= 0.3.0'
   s.add_runtime_dependency 'parallel', '>= 1.12.0'
   s.add_runtime_dependency 'rugged', '>= 0.25.0b2'
-  s.add_runtime_dependency 'puppet', puppet_version
-  s.add_development_dependency 'puppet', puppet_version
+  s.add_runtime_dependency 'puppet', '>= 7'
+  s.add_development_dependency 'puppet', '>= 7'
   s.add_development_dependency 'rspec', '~> 3.4.0'
   s.add_development_dependency 'rake', '12.3.3'
   s.add_development_dependency 'parallel_tests', '2.7.1'
   s.add_development_dependency 'rspec-retry', '0.5.0'
   s.add_development_dependency 'rubocop', '= 0.49.0'
   s.add_development_dependency 'simplecov', '~> 0.14.1'
   s.add_development_dependency 'simplecov-erb', '~> 0.1.1'
-
-  puppet_v = Gem::Version.new(puppet_version)
-  version_config = JSON.parse(File.read(File.join(File.dirname(__FILE__), 'config', 'puppet-versions.json')))
-  version_config.each do |data|
-    next unless puppet_v >= Gem::Version.new(data['minimum_version'])
-    next unless puppet_v <= Gem::Version.new(data['maximum_version'])
-    data['additional_gems'].each do |additional_gem|
-      s.add_development_dependency additional_gem['name'], additional_gem['version']
-    end
-  end
 end