[Bug]: Qwen code from Vertex AI

### What happened?

!litellm.APIConnectionError: Expecting value: line 1 column 1 (char 0). Received Model Group=gcp-qwen3-coder-480b
Available Model Group Fallbacks=None

### Relevant log output

```shell

```

### Are you a ML Ops Team?

No

### What LiteLLM version are you on ?

v1.75.5-stable

### Twitter / LinkedIn details

_No response_