Host OS composite artifact will soon have multiple ROM images #7873
Description
Right now the host OS artifact contains both the phase 1 and phase 2 images for Gimlet. In Cosmo, we will have a new phase 1 image. Currently oxidecomputer/helios#196 tracks how this will change (still tbd). However, whatever logic we have for picking out and assuming image/rom is appropriate for Gimlet is not going to work in the face of Cosmo. This will likely have impacts in everything from wicket through to nexus itself.