F44 Change Proposal: Build FCOS on Fedora Konflux [SelfContained]

[siosm (Timothée Ravier)]

I think we need to reach a consensus on the approach to take for signing. See comments in:

• F44 Change Proposal: Using Konflux for bootc-Based Artifacts [SelfContained] - #5 by siosm
• https://forge.fedoraproject.org/releng/tickets/issues/13115