Remove rubygems_mfa_required setting and disable RequireMFA cop

This setting was introduced automatically by the aforementioned rubocop cop,which makes it impossible to publish to rubygems automatically from a Githubaction with an API key, since one would always need the second factor.

.rubocop.yml

@@ -113,6 +113,9 @@ Metrics/CyclomaticComplexity:
 Metrics/PerceivedComplexity:
   Max: 8
 
+Gemspec/RequireMFA:
+  Enabled: false
+
 # TODO -----------------------------------------------------------------
 
 Style/Documentation:

colorls.gemspec

@@ -81,5 +81,4 @@ Gem::Specification.new do |spec|
   spec.add_development_dependency 'rubocop-rspec', '~> 2.20.0'
   spec.add_development_dependency 'rubygems-tasks', '~> 0'
   spec.add_development_dependency 'simplecov', '~> 0.22.0'
-  spec.metadata['rubygems_mfa_required'] = 'true'
 end