Earthly on M1 with Docker Desktop building containerized linux/arm64 binaries that will execute on the Comma 3

Earthly is so useful. Native linux/arm64 builds (which will be the default when running Docker Desktop on an Apple M1 chip) can be shipped directly to and run fine on a Comma 3!

Unrelated to Earthly, I hope this PR gets merged where I push docker a bit further to make AGNOS (the ubuntu-based OS that powers the Comma 3) buildable on an M1 machine.

A friend informed me that this chip screams, I didn’t believe them at first, but after building a few things with it (agnos, openconnect, and others) I ended up asking the internet why this chip is so fast!

AGNOS usually takes a day to build with an emulated arm environment from a Ryzen 7 chip. On my M1 Air it took about 20 minutes. I think it spent more time sparsifying the final disk image than actually compiling…