[infra] scripting the base images builder

[prabhu]

Our current workflow to build the various variants of container images is copy-pasted and difficult to maintain. Plus, building arm64 images using buildx is too slow. I have some success in getting the split-jobs working in atom, but each image requires three jobs to get this performance.

Instead of more copy-pasting, it will be nice to script these out. Any pointers on how other projects handle this will be much appreciated.

[prabhu]

https://docs.docker.com/build/ci/github-actions/multi-platform/#with-bake

[prabhu]

Thanks to @malice00, this is now implemented with matrices.