multi-arch builds

[janrito]

Is your feature request related to a problem?
My dev machine is an ARM mac, the cluster runs on amd64. Currently I can't build the images locally if I want them to work on the cluster.

Which solution do you suggest?
Buildkit supports multi-arch images https://docs.docker.com/build/building/multi-platform/#multiple-native-nodes

Which alternative solutions exist?

Not aware of any

Additional context

I'd be really nice to just be able to:

images:
  test-application-image:
    image: acct.dkr.ecr.region.amazonaws.com/test-application-image
    dockerfile: app/Dockerfile
    context: app/
    buildKit:
      args: [--platform, 'linux/amd64,linux/arm64']