[CI][Python] Investigate using self-hosted runner for older macOS wheels

[asfimport]

Currently the wheel-macos-high-sierra-\* and wheel-macos-mavericks-\* packages use Github Actions runners in order to get the right macOS version.

But perhaps that could be improved by making it a two-step process?

• the expensive step, which is building the wheel, can be done on a newer macOS version if the right macOS Deployment Target is set

• the cheaper step, which is testing the just-built wheel, can be run on the desired macOS runner

  That way, the very constrained execution capacity available on GHA macOS runners would be less stressed by our CI jobs.

Reporter: Antoine Pitrou / @pitrou

_{Note: This issue was originally created as ARROW-16835. Please see the migration documentation for further details.}

[asfimport]

Antoine Pitrou / @pitrou: @assignUser  Does this sound reasonable?

[asfimport]

Jacob Wujciak / @assignUser: With the new capacity of crossbow this is no longer necessary. But I would like to know if it is really necessary that we build on(or rather for) 10.9 & 10.13 which have been EOL for 5/~2 years both are not available as github runners and even 10.15 will be deprecated soon, so there is no easy way to build/test on these other than setting the deployment target.