adding a chef-zero hard dependency

Signed-off-by: John McCrae <john.mccrae@progress.com>

Author: johnmccrae

oc-chef-pedant/Gemfile

@@ -14,6 +14,7 @@ gem "chef", git: "https://github.com/chef/chef.git", branch: "chef-18"
 
 # For "rake chef_zero_spec"
 # gem 'chef-zero', github: 'chef/chef-zero'
+gem "chef-zero", git: "https://github.com/chef/chef-zero.git", branch: "main"
 
 # If you want to load debugging tools into the bundle exec sandbox,
 # # add these additional dependencies into Gemfile.local