Add arm64 binary

[zeriyoshi]

GCP official repository does not provide binaries for arm64. However, you can build with GOARCH=arm64 to generate a working binary, which will also install Debian packages from the Artifact Registry successfully.

Is there any way to officially support this?

amd64 Packages: https://packages.cloud.google.com/apt/dists/apt-transport-artifact-registry-stable/main/binary-amd64/Packages
arm64 Packages: https://packages.cloud.google.com/apt/dists/apt-transport-artifact-registry-stable/main/binary-arm64/Packages

[zeriyoshi]

I found binaries for arm64 provided as unstable.

https://packages.cloud.google.com/apt/dists/apt-transport-artifact-registry-unstable/main/binary-arm64/Packages

It probably works perfectly. I am waiting for the day when it will move to stable.