I’m trying to locate an RPM for v108.x of Firefox. I tried running “dnf downgrade firefox”, but that only gets up to Firefox 106. I wanted 108 as that’s the last version before they broke the Overflow Menu and forced the Extensions icon on us.
You can find it here
But keep in mind that there could be dependency issues.
Also consider that you can’t use FF 108 forever It would be better to find a suitable solution with the latest version.
A suitable solution will probably require an extension that forces the browser to behave like it did before, or switching to something like Waterfox (not going to use any Chromium-based browsers, that’s for certain).