Made some progress today on building images for arm64 builders, but hit a bit of a snag with the Packer recipes i've found that try to fully replicate a GHA runner with all of Actions' Virtual Environments installed. (For example, this wants to install Homebrew, which doesn't seem to work out of the box on Linux on ARM). But I don't think we need that? I'm guessing it might be best to go for a simpler approach that just installs docker and then we can build a docker image off

<http://quay.io/pypa/manylinux_2_24_aarch64|quay.io/pypa/manylinux_2_24_aarch64>

with a rust toolchain installed in it? I'm not sure what all is needed to build pants or run GHA, but doing something targeted has got to be easier than a kitchen sink approach, right?