ci: Merge db410c support to LAVA container/kernel (and remove llvm from container)
In MR !3661 (merged) I'm working on switching our db410c testing over from docker to LAVA. That's looking good, and we have just a couple of changes left to the rack of HW before we're run a bunch of jobs to verify flakiness and then flip the switch.
This MR merges the container changes that are ready to go, since LAVA container rebuilds are so expensive to do (40 minutes each). whenever I have to rebase on someone else's container change. In the process, I pull in !3904 (closed) and remove LLVM from the container to save initramfs space.