* Apply the retry code to the async pubsub client

Create a test server

```ts
import http from "http";

import { WebSocketServer } from "ws";

let attemptCount = 0;

const server = http.createServer();
const wss = new WebSocketServer({ noServer: true });

wss.on("connection", (ws) => {
  ws.send("Connection accepted.");
  ws.on("message", (msg) => console.log(`Received: ${msg}`));
});

server.on("upgrade", (req, socket, head) => {
  attemptCount += 1;

  if (attemptCount <= 4) {
    socket.write("HTTP/1.1 429 Too Many Requests\r\n\r\n");
    socket.destroy();
    console.log(`Rejected connection #${attemptCount} (429)`);
    return;
  }

  wss.handleUpgrade(req, socket, head, (ws) => {
    wss.emit("connection", ws, req);
    console.log("Connection accepted on attempt", attemptCount);
  });
});

server.listen(8080, () => {
  console.log("Server listening on port 8080");
});
```

Run `test_slot_subscription_async`:

```
Rejected connection #1 (429)
Rejected connection #2 (429)
Rejected connection #3 (429)
Rejected connection #4 (429)
Connection accepted on attempt 5
Received: {"id":1,"jsonrpc":"2.0","method":"slotSubscribe","params":[]}
```

* `s/async_with_retry/with_retry/`