Support for ARM (arm64) architecture?

[larrywest]

Problem

Most of our developer laptops and some of our Kubernetes nodes now run on arm64 architecture (aarch64 on the MacBooks), but the auto-linux and auto-macos assets, as of v11.1.1, are only available for x86-64 (a.k.a. amd64) architecture.

This means we can't use auto everywhere we'd like, which for us and I suspect for many users is either an impediment to using auto or to switching architectures.

PS: Linux has supported arm64 for about a decade, and Apple since 2020 (and has begun winding down support of x86-64/amd64). I do not know about Windows.

Proposed solution

Build and publish assets for the arm64 architecture for Linux and MacOS.

Alternatives

We could build them from source code for our own use, but it seems like the auto team would want to do this anyway.

[hipstersmoothie]

@adierkens you should land that