Make GeckoView take the branch/tags from Firefox
A while ago, we made GeckoView use the same branch as Firefox for desktop (tor-browser#41308 (closed)).
However, we did not change the GeckoView project to use the same branch as Firefox, but we're keeping in sync always (even when we do desktop-only changes or Android-only changes, even though the latter are definitely rarer).
We should modify GV's config to take the same branch as FF automatically. Last nightly, for example, failed because I forgot to update the nightly has on GV.