Update docs/tasks/streams.mdx

Co-authored-by: coderabbitai[bot] <136622811+coderabbitai[bot]@users.noreply.github.com>

Author: ericallam

docs/tasks/streams.mdx

@@ -610,7 +610,7 @@ cancelSignal.on((data) => {
   console.log("Cancelled:", data.reason);
   controller.abort();
 });
-const result = await streamText({ ..., abortSignal: controller.signal });
+const result = streamText({ ..., abortSignal: controller.signal });
 ```
 
 #### `peek()` — Non-blocking check