composefs & UKI: Staging an update, then switching to another image will leave the staged UKI in the ESP

I'll have to reproduce this one to get the exact steps but I did something like the following on a composefs + uki system: - I staged an update with bootc update - Then I switched to another image using bootc switch - Then I rebooted - I got offered the staged update (which should have been cleaned up by the switch) - Booting the "correct" switched image, bootc was no longer able to figure out the rollback deployment and failed on most commands (at least status) - here we should likely just pick one and move on and never fail - I had to manually clean up 2 UKIs and 1 BLS entry to get back to a working system.