Turn on zstd:chunked

[castrojo]

https://bootc-dev.github.io/bootc/experimental-unified-storage.html

Synced with Joseph at kubecon, we can start turning on zstd:chunked in our workflows (I think we do it on push?). Systems that don't support it fail back gracefully.

Note that this is complementary to chunkah, so they shouldn't block each other - endstate is having both.

Something like this:

podman push \
   --compression-format=zstd:chunked \
   --compression-level=3 \
   ghcr.io/ublue-os/...:${TAG}

cc @KyleGospo @renner0e