Create a container image with all Python versions supported by Spack.

The spack.yaml file contains a list of Python versions and their hashes (as they are built in Gitlab CI).

To publish a new container image, update the spack.yaml file and run

GHCR_USER=... GHCR_PASS=... spack -e . buildcache push \
    --tag YYYY-MM-DD \
    --unsigned \
    --base-image ubuntu:24.04 \
    --without-build-dependencies \
    ghcr