[ci] appveyor improvements, test on a wider range of ruby versions

[lacostej]

Extracted from #21685 which will take time to land.

This also resolves #21684 (for those using ruby 2.7 and above).

Checklist

• I've run bundle exec rspec from the root directory to see all new and existing tests pass
• I've followed the fastlane code style and run bundle exec rubocop -a to ensure the code style is valid
• I see several green ci/circleci builds in the "All checks have passed" section of my PR (connect CircleCI to GitHub if not)
• I've read the Contribution Guidelines
• I've updated the documentation if necessary.
• I've added or updated relevant unit tests.

Motivation and Context

Description

Testing Steps