Do not expose fairCrossWith

We can just use `fairCross` followed by `map` and it should fuse.

Author: harendra-kumar

core/src/Streamly/Data/Stream.hs

@@ -567,7 +567,7 @@ module Streamly.Data.Stream
     -- "crossMap" or "nestWith".
     , crossWith
     , cross
-    , fairCrossWith
+    -- , fairCrossWith
     , fairCross
     -- , joinInner
     -- , CrossStream (..)