Support for Mac runner simulation

[verdverm]

I have an OS matrix build. Sometimes there are only errors in the mac build because reasons. I end up pushing debug commits and minor adjustments... (example: https://github.com/hofstadter-io/hof/actions/runs/5992905676)

I would love to be able to fix these issues with gale. My current issue revolves around using docker via the cli on a default mac worker, to pull & run images only, by running the docker cli "by hand" and via a Go Exec call from our own cli. We are testing whether our cli can run the docker cli.

If this requires actual mac hardware, that is probably fine, though it would be great if it supported a cloud based. We are considering hooking one of these services up to GHA custom workers, which might make the env more predictable and debugable. Basically everyone's builds have been failing due to an unentitled (not signed) qemu binary (v8.0.4)

Here is the issue, on the github action we use to setup docker on mac. crazy-max/ghaction-setup-docker#18 (comment) This would be a good action for macos gale to test with.