removing freebsd from kitchen.yml generator template

[Stromweld]

Description

Removing freebsd since it's not supported anymore by chef-client

Related Issue

Types of changes

• [ ] Bug fix (non-breaking change which fixes an issue)
• [ ] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to change)
• [x] Chore (non-breaking change that does not add functionality or fix an issue)

Checklist:

• [x] I have read the CONTRIBUTING document.
• [x] I have run the pre-merge tests locally and they pass.
• [x] I have updated the documentation accordingly.
• [x] I have added tests to cover my changes.
• [x] If Gemfile.lock has changed, I have used --conservative to do it and included the full output in the Description above.
• [x] All new and existing tests passed.
• [x] All commits have been signed-off for the Developer Certificate of Origin.