OpenRGB

I was hesitant to update the Flatpak build to a release candidate, but 1.0rc2 is the build we're recommending on openrgb.org and a bunch of distros have packaged it. To be fair, if there were more digits between 0.9 and 1.0 these rcs would've been proper releases. With a lot of users having success with 1.0rc2 on other platforms, 1.0 still being a ways out do to some backend reworks and cleanups, and 0.9 being ancient now, I've gone ahead and updated the Flatpak release to 1.0rc2. You will still have to setup udev rules outside of Flatpak, as that is a limitation of Flatpak itself.