We should be able to take CDN certificates to authenticate to RH Flatpak registries.

Also, we should somehow resolve staging CDN.

This could be more demanding from level of testing as before release we have only staging CDN available. To test this on real CDN, I can use RHEL-10.0 (released GA) ISO image and use updates image with my changes to get Flatpaks from official CDN. Or build the ISO from RHEL-10.0 compose.