Don't set isIdle when it is not in fact idle (#24274)

### What does this PR do?

### How did you verify your code works?


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## Summary by CodeRabbit

* **Bug Fixes**
* Improved HTTP connection handling during write failures to ensure more
reliable timeout behavior and connection state management.

<!-- end of auto-generated comment: release notes by coderabbit.ai -->

packages/bun-uws/src/HttpContext.h

@@ -412,7 +412,6 @@ private:
                 /* Timeout on uncork failure */
                 auto [written, failed] = ((AsyncSocket<SSL> *) returnedData)->uncork();
                 if (written > 0 || failed) {
-                    httpResponseData->isIdle = true;
                     /* All Http sockets timeout by this, and this behavior match the one in HttpResponse::cork */
                     ((HttpResponse<SSL> *) s)->resetTimeout();
                 }