fix: o-series model compatibility

[dexhunter]

• fix unable to run o-series model
• remove extra line

[dexhunter]

friendly request for review @simonguozirui @alexzhang13

openai.BadRequestError: Error code: 400 - {'error': {'message': "Unsupported parameter: 'max_tokens' is not supported with this model. Use 'max_completion_tokens' instead.", 'type': 'invalid_request_error', 'param'
: 'max_tokens', 'code': 'unsupported_parameter'}}

or can change max_tokens to max_completion_tokens if needed, while I suppose those two have different usages

[simonguozirui]

@dexhunter thanks for highlighting this and your contribution. Generally, I am gonna replace the LLM client call with litellm as described in #70, as model interfaces keep changing now.