chore: ignore unenv issue

Author: pi0

src/adapters/plain.ts

@@ -80,6 +80,7 @@ export async function _handlePlainRequest(app: App, request: PlainRequest) {
   nodeReq.headers = Object.fromEntries(headers.entries());
 
   // Create new event
+  // @ts-expect-error unenv polyfill lacks ServerResponse.setHeaders
   const event = createEvent(nodeReq, nodeRes);
 
   // Fill internal event properties