This commit switches the default repositories to use the build-in
ones from images PR#1112. It is still possible to override using
`/etc/image-builder` and `/usr/share/image-builder` or `--datadir`.
This is implicitly tested via the container test that no longer
includes the files from osbuild-composer in the container.
This commit adds a smoke test that builds the ibcli container
and runs a fedora-41 raw-minimal build to double check that
the container based building actually works.
Thanks to Ondrej for suggesting this.