Switch to BUILDX to build images

[potiuk]

We should use buildx to build and cache our image

https://docs.docker.com/buildx/working-with-buildx/

In the past it was difficult because we are heavily use caching of the imges and the cache of BUILDX was not compatible with docker registry. Howvever with moving to GHCR.io and improvements in Buildx infrastructure it should now be possible to push and pull cache which will be both BUILDX and regular docker build compatible.