chore: remove __stream__

Author: polvalente

nx/lib/nx/defn/sharding_compiler.ex

@@ -175,11 +175,6 @@ defmodule Nx.Defn.ShardingCompiler do
     end
   end
 
-  @impl true
-  def __stream__(_key, _input, _acc, _vars, _fun, _args_list, _opts) do
-    raise "__stream__ not supported"
-  end
-
   @impl true
   def __partitions_options__(_keyword) do
     raise "__partitions_options__ not supported"