Docker image does not start on ARM servers

I tried to use the docker image via `az aks check-acr` to debug an unrelated issue, and got:

`standard_init_linux.go:228: exec user process caused: exec format error`

I suspect that happens because the node pool uses Dps v5 (ARM Ampere) servers, after switching to Intel servers it worked. Building on ARM works fine, but there is no ARM build in the makefile.

Start with the Makefile, which the issue identifies as lacking an ARM build, and inspect how the Docker image is built. Verify the resulting image can start on ARM Ampere nodes through az aks check-acr without the exec format error, while preserving the existing Intel build.

Written by the indexing model from the issue text.