[client] Add retry backoff when disk protection rejects writes

### Search before asking

- [x] I searched in the [issues](https://github.com/apache/fluss/issues) and found nothing similar.

### Motivation

When a TabletServer enters disk write protection, it rejects incoming writes. However, clients continue retrying too aggressively and repeatedly send the write payloads to the server.

In our observed incident, this retry traffic saturated network I/O even though the server was already rejecting writes. This also made troubleshooting confusing: network utilization remained high while successful writes were blocked by disk protection.

Client-side retry backoff would reduce unnecessary traffic and resource consumption while allowing writes to recover automatically when disk protection is lifted.

### Solution

_No response_

### Anything else?

_No response_

### Willingness to contribute

- [ ] I'm willing to submit a PR!