This patch splits the former DEPOT=omit option into two variants.
The new 'list' option behaves like the former 'omit' option, skipping
the creation of the tar archive from the depot content referenced by the
deploy configuration but showing a list of depot archives that need to
be published for the deployment.
When specifying 'omit' in th new version, the local depot is not queried
for the packages referenced in the deploy configuration. So the
deployment can refer to packaged hosted only remotely.
Fixes#4605
5b4b243e3d