shared_lib.sh now contains some more helper functions and the
verification script uses them. Copy it over so that we can source it.
Also install all other dependencies before the actual upgrade.
This test provisions a RHEL-8.6 VM locally, installs osbuild-composer on
it, upgrades the system to RHEL-9.0 and verifies osbuild-composer still
works by building a simple qcow image.
