Goal:

Foreman and Foreman Proxy are only deployed on Ruby 3.0+ environments. More any more gems are dropping support for Ruby 2.7. Dropping older Ruby support allows updating gems to more recent versions.

Acceptance Criteria:

• Foreman and plugins no longer test on Ruby 2.7, both upstream and downstream
• Foreman Proxy and plugins no longer test on Ruby 2.7, both upstream and downstream
• Hammer and plugins no longer test on Ruby 2.7, both upstream and downstream
• Foreman installer no longer tests on Ruby 2.7, both upstream and downstream