Use latest Omicron zone packaging

[pfmooney]

This updates our use of omicron-zone-package to the latest version, dropping a bunch of outdated deps from the tree in the process.

It should not be merged until oxidecomputer/omicron-package#75 is addressed, since the OVMF and Alpine blobs are otherwise missing from the resulting tarball.

[pfmooney]

With omicron-zone-package 0.12.1 now published to crates.io, this should be ready to go.

[pfmooney]

Testing notes:

Running the existing propolis-package and the "new" one (built from this change) yielded output tarballs which were practically identical. The only difference (as checked with rsync between extracted directories) was the time attributes on the blob directory.

sending incremental file list
.d..t...... ./
.d..t...... root/opt/oxide/propolis-server/blob/

sent 538 bytes  received 37 bytes  1,150.00 bytes/sec
total size is 113,749,506  speedup is 197,825.23 (DRY RUN)