[TubeSync-fs] Check for cookiefile option directly

[tcely]

To enable this cache you must create the directory manually:

mkdir -v -p /config/cache/yt-dlp/youtube-pot

Nothing is going to clean up the files this creates, so it is marking itself unavailable for now.

I think using huey storage is the better option.

See also:

• [TubeSync-huey] Create cache-huey.py #1150