(hot)fix: pin key4hep-spack to yesterday
This PR pulls key4hep-spack out of irreproducibility and bases it on a fixed commit hash. It also removes unused and discouraged cherry-picks on eic-spack and key4hep-spack.
This PR pulls key4hep-spack out of irreproducibility and bases it on a fixed commit hash. It also removes unused and discouraged cherry-picks on eic-spack and key4hep-spack.