Docker build warnings

[faisal-memon]

Running make docker-build results in the following warnings:

 2 warnings found (use --debug to expand):
 - InvalidDefaultArgInFrom: Default value for ARG golang:${go_version}-alpine results in empty or invalid base image name (line 3)
 - Requested platforms linux/arm64 do not match result platforms linux/amd64,linux/arm64
 - ```