(MAINT) Bump minumum ruby version

This commit bumps the minimum ruby requirement to 2.7.

Author: chelnak

Diff for: puppet-strings.gemspec

@@ -12,7 +12,7 @@ Gem::Specification.new do |s|
   s.summary = 'Puppet documentation via YARD'
   s.email = '[email protected]'
   s.homepage = 'https://github.com/puppetlabs/puppet-strings'
-  s.required_ruby_version = '>= 2.5.0'
+  s.required_ruby_version = '>= 2.7.0'
 
   s.extra_rdoc_files = [
     'CHANGELOG.md',