I just saw the sqlite-shm corruption in
https://gitlab.com/redhat/centos-stream/containers/bootc/-/merge_requests/437#note_2372766792
so let's just go ahead and turn on rpmdb_normalize which
also aids the reproducibility of the rpmdb.
While we're here let's also add a long overdue "unit test" for
the rootfs. This operates as a container build that mounts
the container-under-test as part of a multi-stage build.
Signed-off-by: Colin Walters <walters@verbum.org>
