Remove abortAfterTimeout

It's fundamentally flawed because it doesn't support easy cancellation of the timeout.

src/shared/protocol.ts

@@ -48,8 +48,6 @@ export type RequestOptions = {
 
   /**
    * Can be used to cancel an in-flight request. This will cause an AbortError to be raised from request().
-   *
-   * Use abortAfterTimeout() to easily implement timeouts using this signal.
    */
   signal?: AbortSignal;
 };