Not all OpenAI compatible endpoints and models on an endpoint support all variables

[andrewginns]

Need a better way to handle this then just to remove all variables until a common set is found.

• OpenAI documentation https://platform.openai.com/docs/api-reference/chat/create

e.g. Mistral models on Azure AI don't support frequency_penalty or presence_penalty.

There might be a way to query and endpoint first to determine what variables are supported.