Require Ruby < 3.2

Ruby 3.2 removed Object#taint and #tainted?. One of beaker-puppet's
depenencies, inifile, uses those methods.

This commit updates the gemspec to limit usage on Ruby 3.2 and above.

Also see: puppetlabs#206

beaker-puppet.gemspec

@@ -11,7 +11,7 @@ Gem::Specification.new do |s|
   s.description = 'For use for the Beaker acceptance testing tool'
   s.license     = 'Apache-2.0'
 
-  s.required_ruby_version = '>= 2.7'
+  s.required_ruby_version = '>= 2.7', '< 3.2'
 
   s.files         = `git ls-files`.split("\n")
   s.test_files    = `git ls-files -- {test,spec,features}/*`.split("\n")