Deprecate the extra codecs option.
Split the codec option off from #22910 (closed) since they technically are two separate things. Relevant details from the original ticket are as follows:
Having massive "foot + gun" options in general is bad practice.
The extra codecs will expose ffmpeg to the browser container, which is a concrete increase in attack surface for questionable gain (gstreamer is never allowed).
It looks like the browser people sort of considered the ffmpeg situation at #18946 (moved), and I initially added the pref in #20806 (closed). Really what should happen is that Tor Browser should bundle their own copy if it's that critical to functionality instead of pulling in one of 7 different .so files via dlopen (dom/media/platforms/ffmpeg/FFmpegRuntimeLinker.cpp
).