Code review comment for ~paelzer/ubuntu/+source/qemu:4.2-3-for-focal

In my discussion with Debian-qemu this morning it became clear they might soon add microvm into the main qemu-system-x86 package. If so we'd likely follow, there is no extra
burden to maintain src:qemu due to that.

But until then keep it split as I have suggested initially in
https://salsa.debian.org/qemu-team/qemu/merge_requests/10

Once we follow, that will just be a bunch of breaks/replaces and we are good.
Even if we decide to stay split, the delta to move to a different package is much smaller than the one adding the whole build.