refactor: move handled set to proxy util

Author: pi0

src/core/dev-server/proxy.ts

@@ -33,6 +33,7 @@ export function createHTTPProxy(defaults: ProxyServerOptions = {}): HTTPProxy {
 
   const handleEvent = async (event: H3Event, opts: ProxyServerOptions = {}) => {
     try {
+      event._handled = true;
       await proxy.web(event.node.req, event.node.res, opts);
     } catch (error: any) {
       if (error?.code !== "ECONNRESET") {

src/core/dev-server/worker.ts

@@ -59,7 +59,6 @@ export class NodeDevWorker implements DevWorker {
         statusText: "Dev worker is unavailable",
       });
     }
-    event._handled = true;
     await this.#proxy.handleEvent(event, { target: this.#address });
   }