[Improve][SDK] Fix panic on sending to a closed channel during shutdown in the DataProxy Go SDK

### Description

In the Dataproxy Go SDK, sending on the already-closed sendFailedBatches, retryBatches, or responseBatches channels during shutdown can raise a "send on closed channel" panic and crash the process.

### InLong Component

InLong SDK

### Are you willing to submit PR?

- [x] Yes, I am willing to submit a PR!

### Code of Conduct

- [x] I agree to follow this project's [Code of Conduct](https://www.apache.org/foundation/policies/conduct)

Start by locating the Dataproxy Go SDK code that owns the sendFailedBatches, retryBatches, and responseBatches channels, then trace shutdown and every send to those channels. Reproduce or run the SDK shutdown-related tests if available. Done means shutdown no longer permits a send-on-closed-channel panic or process crash.

Written by the indexing model from the issue text.