beets: Remove acousticbrainz plugin

With the sunsetting of acousticbrainz I think it is time to
confront reality and remove the plugin. Was a lot of fun to
play around with and create playlists from that followed
music beats, mood or similar but ultimately it slowed down
importing a lot and I never earnestly used it for anything.

multimedia/.config/beets/config.yaml

@@ -60,7 +60,6 @@ match:
   rec_gap_thresh: 0.25
 
 plugins:
-  - acousticbrainz
   - bandcamp
   - chroma
   - deezer