fix: install correct mc binary for arm64
Instead of installing the amd64 binary for mc
into the container, we now install the arm64 binary for arm64 target platforms. We continue to use ADD for layer caching, rename the appropriate binary per TARGETPLATFORM to simply mc
, then remove the others again. This is a bit inefficient as layers go, but this is a 24MB binary and it is only done for the staging container.