fix: custom websocket server not upgrading due to next 13.4.3+

It seems next v13.4.3 added a breaking change that causes sockets to be closed when not handled by HMR. As a result, websocket connections fail to upgrade. I've applied a fix from the following thread to address this issue for now:

vercel/next.js#50461 (comment)

src/server/prodServer.ts

@@ -10,6 +10,7 @@ const port = parseInt(process.env.PORT || '3000', 10);
 const dev = process.env.NODE_ENV !== 'production';
 const app = next({ dev });
 const handle = app.getRequestHandler();
+const upgradeHandler = app.getUpgradeHandler();
 
 void app.prepare().then(() => {
   const server = http.createServer((req, res) => {
@@ -33,6 +34,15 @@ void app.prepare().then(() => {
     console.log('SIGTERM');
     handler.broadcastReconnectNotification();
   });
+
+  server.on('upgrade', upgradeHandler);
+
+  // Keep the next.js upgrade handler from being added to our custom server
+  // so sockets stay open even when not HMR.
+  const originalOn = server.on.bind(server);
+  server.on = function (event, listener) {
+    return (event !== 'upgrade') originalOn(event, listener) : server;
+  };
   server.listen(port);
 
   console.log(