## Description

In `test_model_connection` (`litellm/proxy/health_endpoints/_health_endpoints.py`), `_update_litellm_params_for_health_check` is called with a hardcoded `model_info={}` instead of passing the actual `model_info` from the request. This means `health_check_supports_max_tokens: false` set in `model_info` is silently ignored when using the UI "Test Connection" button — `max_tokens: 5` is always injected regardless of the setting.

## Steps to Reproduce

1. Add a model to `config.yaml` with `model_info: { health_check_supports_max_tokens: false }`: ```yaml model_list: - model_name: my-model litellm_params: model: openai/my-deployment api_base: https://... api_key: ... custom_llm_provider: openai model_info: health_check_supports_max_tokens: false ``` 2. Start LiteLLM proxy and go to the UI → Models tab 3. Click **"Test Connection"** for that model 4. Observe the outgoing request to the backend — it includes `max_tokens: 5`

## Expected Behavior

`max_tokens` should **not** be sent when `health_check_supports_max_tokens: false` is configured, matching the behavior of the background `/health` endpoint…