chore: cleanups from code review

Allow WSServerDelegate.onConnection to return undefined instead of a
no-op connection, align the upgrade 403 status line in HttpServer with
WSServer.

Author: yury-s

packages/playwright-core/src/tools/mcp/cdpRelay.ts

@@ -102,7 +102,7 @@ export class CDPRelayServer {
           this._handlePlaywrightConnection(ws);
         else
           this._handleExtensionConnection(ws);
-        return { close: async () => {} };
+        return undefined;
       },
     });
   }

packages/utils/httpServer.ts

@@ -90,7 +90,7 @@ export class HttpServer {
       if (pathname !== wsPath)
         return;
       if (!isAllowedHost(request, this._allowedHosts)) {
-        socket.write('HTTP/1.1 403 Forbidden\r\n\r\n');
+        socket.write(`HTTP/${request.httpVersion} 403 Forbidden\r\n\r\n`);
         socket.destroy();
         return;
       }

packages/utils/wsServer.ts

@@ -46,7 +46,7 @@ export type WSServerDelegate = {
   onRequest: (request: http.IncomingMessage, response: http.ServerResponse) => void;
   onHeaders: (headers: string[]) => void;
   onUpgrade: (request: http.IncomingMessage, socket: stream.Duplex) => { error: string } | undefined;
-  onConnection: (request: http.IncomingMessage, url: URL, ws: WebSocket, id: string) => WSConnection;
+  onConnection: (request: http.IncomingMessage, url: URL, ws: WebSocket, id: string) => WSConnection | undefined;
   isAllowedPathname: (pathname: string) => boolean;
 };