To ensure stable CI testing of DNF payload support in the Web UI, we need to
set up and use a local repository server instead of relying on external Fedora
mirrors. This will prevent rate limiting and improve test reliability.

The task includes:

• Preparing a local repository with the necessary packages.
• Configuring CI to use this local repo for DNF payload installation tests.
• Verifying that an installation with DNF payload completes successfully in CI.