Don't special-case TransformStream readables when streaming outgoing …

…bodies

This special-casing used to make sense in the JS-Compute runtime, where certain TransformStreams were more optimizable. It doesn't anymore, and in any case would have to come with actually reading from the stream, which the code as written before this patch didn't 🤷

builtins/web/fetch/request-response.cpp

@@ -1050,14 +1050,6 @@ bool RequestOrResponse::maybe_stream_body(JSContext *cx, JS::HandleObject body_o
     return false;
   }
 
-  if (streams::TransformStream::is_ts_readable(cx, stream)) {
-    JSObject *ts = streams::TransformStream::ts_from_readable(cx, stream);
-    if (streams::TransformStream::readable_used_as_body(ts)) {
-      *requires_streaming = true;
-      return true;
-    }
-  }
-
   // If the body stream is backed by an HTTP body handle, we can directly pipe
   // that handle into the body we're about to send.
   if (streams::NativeStreamSource::stream_is_body(cx, stream)) {