chore: spack: avoid need for protobuf +cpp

This cherry-picks the upstream work on making protobuf +cpp unnecessary, enabling us to upgrade some python components.

containers/jug/dev.Dockerfile

@@ -72,7 +72,6 @@ make --jobs ${jobs} --keep-going --directory /opt/spack-environment \
   SPACK_ENV=${SPACK_ENV} \
   BUILDCACHE_OCI_PROMPT="eicweb" \
   BUILDCACHE_OCI_FINAL="ghcr"
-spack gc --yes-to-all
 spack find --long --no-groups \
 | sed -e '1,/Installed packages/d;s/\([^@]*\).*/\1/g' \
 | uniq -D -f1 | grep -v -w -e "\(epic\|py-pip\|py-cython\)" \