Capping quality against an Emby server on macOS (or any device with an
AV1 decoder) failed with HTTP 500: Emby takes the first entry of the
TranscodingProfile codec list verbatim and has no AV1 encoder. Jellyfin
rotates admin-disabled codecs to the back, which is what the AV1-first
list relied on. Gate AV1 on that dialect behavior.
close#2230