Related Issues

Resolves #12860

Proposed Changes

Start running unit-* jobs on arm64 machines in addition to x86_64 ones.

Additional Info

In order to accommodate this change, I moved the test discovery code to a dedicated Go CLI. The important change in the structure of metadata is that now each test group can be associated with many target runners.

What's more, I split the test group discovery into part 1 which lists all the test groups, and part 2 which returns the metadata (e.g. runner information, etc.) for a given test group name. Thanks to this the outputs of the discovery job can be smaller and we minimise the risk of hitting the maximum output size limit.

Checklist

Before you mark the PR ready for review, please make sure that:

• Commits have a clear commit message.
• PR title conforms with contribution conventions
• Update CHANGELOG.md or signal that this change does not need it per contribution conventions
• New features have usage guidelines and / or documentation updates in
  • Lotus Documentation
  • Discussion Tutorials
• Tests exist for new functionality or change in behavior
• CI is green