Validate Lite LLM Support

[matifali]

Some Coder customers have already deployed LiteLLM internally and have also set it up to work with Coder. With Ai Bridge rolling out there can be two scenarios

1. They replace LiteLLM with AI Bridge (which is ulikky at this stage as Coder Bridge is still minimal and not a full blown LLM gateway)
2. They configure AiBridge to work along with existing LiteLLM.

This objective here is to validate 2.

https://www.litellm.ai/

[matifali]

Validated with both Anthropic and OpenAI endpoints.
Need to document?

[matifali]

Reopening, as we do not yet have any guides or docs on how to configure. The docs can be as simple as pointing to upstream docs to configure a client.

Initial validation shows that setting the base URL and a valid LiteLLM token for the bridge config is sufficient.

@jatcod3r, can you summarize the high-level steps on how to set it up?

Thanks.