MetaCall Builder

Work in progress.

go build -o builder && ./builder deps python | ./hack/buildctl.sh build --output type=docker,name=metacalldemo:deps-py | docker load

Maybe staging package is not necessary, it can be done in the builder package.

In DEMO, deps = dev-deps-base + core-repo + core-build + py-env - dev-deps-base - core-repo = core-build + py-env