Add caching for image builds

[lgautier]

No description provided.

[kiendang]

By caching do you mean caching the packages downloaded by apt and pip? That is possible using buildkit with the experimental Dockerfile syntax.

[lgautier]

I meant meant caching the parent images. here are 3 images in direct filiation, base -> jupter -> jupyter_ds, and the action will rebuild all three even if a push only modifies jupyter_ds.

Thanks for pointing out buildkit. This could also help here.