CI: Availability of arm64 runners

[jamesx-improving]

Currently we have only one self-hosted arm64 runner for all linux arm64 GHA workflow jobs. Sometime the queue can be long.

Also, no forked repo will have access to the self-hosted runner either.

Would be great if we could expand the number of self-hosted arm64 runners, or switch to GH hosted arm64 runner (in preview, was not available when this project started).

Also, explore the possibility to allow forked repo to have access to self-hosted arm64 runners, if that's the path moving forward.

[adarovadya]

hey
The issue in-progress. Duplicate of #2037