[BUG] Not able to fetch lossless format

[yeralin]

Describe the bug
Whenever you are trying to fetch AudioQuality.LOSSLESS, it logs:

Using VORBIS format file with VERY_HIGH quality because preferred LOSSLESS quality couldn't be found.

To Reproduce
Steps to reproduce the behavior:

1. Set quality to AudioQuality.LOSSLESS
2. Try to fetch the audio file using content_feeder

Expected behavior
Fetches lossless (FLAC) audio format.

Additional context
According to this closed PR (#316) that introduced LOSSLESS support from @akbad:

@Googolplexed0 I tried the same thing and sadly it didn't work properly. I looked into it and my conclusion is that everything in this PR is indeed needed to support FLAC, and it's simply the Spotify endpoints used that aren't serving FLAC files in response to our requests.
My guess is that there's some secret sauce in the Spotify desktop client's requests that we need to replicate somehow here in order to get it to serve us FLAC files. I tried tracing how Spotify's desktop client does it (i.e. using mitmproxy) but didn't have enough time to completely figure it out (and won't for a little while sadly). Whenever this is done, it would probably provide the missing piece to the puzzle.

[DarpNagarsheth]

I have a suspicion that Spotify doesn't have that track in FLAC. Is there any way to confirm it's available on their end

[yeralin]

No, it is related to this issue librespot-org/librespot#1583

It seems like librespot will not pursue trying to work with / fetch lossless format.