Building new OpenShot (and libs) for branches only

OpenShot released a new version 2.4.4 earlier this week, so I'm readying new builds of the libopenshot-audio, libopenshot, and openshot packages for the f29 and f28 branches. libopenshot-audio is still FTBFS in rawhide due to GCC 9, so the new version *won't* be built there. I seem to recall that this exact situation was presented as an example scenario that would exempt a package from the "must be built in rawhide first" rule, though I can't find that particular exception now. (Nor can I even remember whether it's an rpmfusion rule, or part of the Fedora packaging guidelines themselves.) Anyway, just a heads-up to explain the unusual situation. (Regarding the libopenshot-audio FTBFS problem, it's been reported upstream but the developers wanted to get the release out first before tackling it. Hopefully now that's been done, we'll see some movement on GCC 9 compatibility.)