QA:Testcase Preupgrade from older release

Description

This case tests upgrading a Fedora system from the previous stable release (Fedora 40) to the branched release (Fedora 42) using PreUpgrade.

How to test

1. Perform an installation of the stable release (e.g. Fedora 40) with default partitioning (500MB for /boot).
2. Install the newest available version of preupgrade and python-urlgrabber
3. Run preupgrade from a command prompt or the Run Application dialog. Provide the requested password for root authorization.
4. On the Choose desired release screen, enable unstable test releases.
5. Choose Fedora 42 (Branched) from the list of available upgrade targets, then click Apply.
6. When the process completes, click Reboot.
7. The system should reboot, perform the upgrade, and reboot into the new system automatically.
8. Log in to upgraded system, open a terminal, file browser, or other system applications.

Expected Results

1. The preupgrade utility will run to completion, without error
2. The upgrade should complete and reboot without user assistance.
3. The user is not prompted to address low disk space in /boot
4. The system should be upgraded to new version without error.
5. The opened terminal, file browser, or other system applications should display and work correctly.