Remove redundant optional fairseq dependency.

Author: agkphysics

setup.cfg

@@ -88,8 +88,6 @@ audioset =
     tensorflow-hub
 encodec =
     encodec
-fairseq =
-    fairseq
 huggingface =
     transformers
 keras_apps =
@@ -108,7 +106,6 @@ all-preprocessors =
     %(encodec)s
     %(opensmile)s
     %(phonemize)s
-    %(fairseq)s
     %(huggingface)s
     %(keras_apps)s
     %(speechbrain)s