Support running natively on aarch64 / arm64 hosts / Mac M1/M2

[Emilgardis]

Checklist

• I've looked through the issues and pull requests for similar request
• This feature could be solved with a custom docker image (optional)

Describe your request

With the rise of arm64 architecture, cross should natively support this host architecture.

This means that the docker images should run on aarch64, and that cross should not make assumptions that the host is x86_64.

Describe why this would be a good inclusion for cross

No response

[Emilgardis]

prior work: #567

[Emilgardis]

One issue with this is that as mentioned, ubuntu does not ship the same packages for arm64 as it does for x86_64.

Another issue is how we should solve building the images. I think we could use buildx, but that would severely increase CI time I think