ENH: support linux-aarch64

[corneliusroemer]

Context

Bioconda has supported linux-aarch64 for a few months now and all augur deps are available now on that aarch.

Making conda-base support linux-aarch64 would have the advantage that we could make all of our docker containers simply with micromamba docker base image.

It seems all the recipe.yaml dependencies are already supported by linux-aarch64.

So all we'd need to do is make a package for it.

One challenge for linux-aarch64 is that Github actions doesn't have native aarch64 runners (yet).

[victorlin]

Actually GitHub recently announced the public beta of aarch64 runners under the "larger runners" category (docs links in the final paragraph).

I just tried setting it up under @nextstrain. Looks like it's a paid service to be enabled via billing updates: