This was motivated by the fact that recording was crashing on the native
M1 build. That ended up being mostly a PEBKAC problem - turns out the
Mac Mini has no built-in microphone 🤦.
I still thinks this has some value though - it doesn't crash in such
cases, and probably doesn't suffer from the problem shown in this thread
either:
https://forums.ankiweb.net/t/anki-crashes-when-trying-to-record-on-mac/14764
For now, this is only enabled when running on arm64. If it turns out to
be reliable, it could be offered as an option on amd64 as well.