Repo without any source is silently ignored with skip_if_unavailable=1

[kontura]

Given an empty.repo configured as:

[empty]
name=empty
enabled=1
gpgcheck=0

(there is no baseurl, mirrorlist or metalink)

Running:

$ dnf5 makecache --refresh --repo empty --setopt=skip_if_unavailable=1
Updating and loading repositories:
Repositories loaded.
Metadata cache created.

It would be nice to let the user know the enabled repo wasn't updated, similarly to dnf4:

$ dnf4 makecache --refresh --repo empty --setopt=skip_if_unavailable=1
Error: Cannot find a valid baseurl for repo: empty
Ignoring repositories: empty
Metadata cache created.

This is tested in https://github.com/rpm-software-management/ci-dnf-stack/blob/main/dnf-behave-tests/dnf/repo-sync.feature