When installing from the Server DVD, the package repo on the DVD itself should be mounted at /run/install/repo and used as the main repo by anaconda.

However, since Fedora-Rawhide-20230716.n.0, this is not happening. When you run an install from the Server DVD, the installer UI shows "Closest mirror" as the "Installation Source", not "Auto-detected source" as it did before. If you go to a console, you'll find that /run/install/repo is not mounted.

anaconda did not change between 20230715.n.0 and 20230716.n.0, neither did anything else obviously relevant, so systemd - which *did* change, from 253.5-6.fc39 to 254~rc2-1.fc39, in the affected compose - seems like the most obvious suspect here.

Reproducible: Always

Steps to Reproduce:
1. Get Fedora-Server-dvd-x86_64-Rawhide-20230716.n.0.iso or later
2. Boot it
3. Observe the Installation Source, check logs
Actual Results:  
It uses a remote mirror as the primary install repo

Expected Results:  
It should use the DVD's own package repo

This is why the openQA VNC install tests are failing (these tests are setup such that external network access doesn't work, so the test fails because it cannot reach any mirror). The fact that no other openQA test fails is a bit of an oversight, we should have at least one test which checks that the DVD install actually uses the DVD package source - we check this for other repo configs, but we don't check it in this case.