When we used the dnf-based pipelines, we were relying on the fact
that the metadata was unlikely to have changed between we generated
the pipeline and called osbuild. We achieved this by always updating
to the most recent metadata on every call to rpmmd.Depsolve that
would end up in a pipelin.
Refreshing the metadata is time-consuming, and something we want
to avoid if at all possible. Now that our pipelines no longer
rely on this property, we can drop the flushing.
Signed-off-by: Tom Gundersen <teg@jklm.no>
819430e659