[Bug]: Can not generate commuty report using default settings in get_started.md

[zhichao-aws]

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• I have searched the existing issues and this bug is not already filed.
• My model is hosted on OpenAI or Azure. If not, please look at the "model providers" issue and don't file a new one here.
• I believe this is a legitimate bug, not just a question. If this is a question, please use the Discussions area.

Describe the bug

I followed the tutorial in get_started.md to index the book, but found it didn't generate the community reports. And I found these exceptions in log:

               ^^^^^^^^^^^^^^^^^^^
  File "/Volumes/workplace/community/graphrag/.venv/lib/python3.12/site-packages/litellm/llms/openai/openai.py", line 859, in acompletion
    raise OpenAIError(
litellm.llms.openai.common_utils.OpenAIError: Error code: 400 - {'error': {'message': "Invalid parameter: 'response_format' of type 'json_schema' is not supported with this model. Learn more about supported models at the Structured Outputs guide: https://platform.openai.com/docs/guides/structured-outputs", 'type': 'invalid_request_error', 'param': None, 'code': None}}

After switch the model to gpt-4o in settings.yaml, it ran as expected. Can we change the default model in this repo?

Steps to reproduce

No response

Expected Behavior

No response

GraphRAG Config Used

# Paste your config here

Logs and screenshots

No response

Additional Information

• GraphRAG Version:
• Operating System:
• Python Version:
• Related Issues:

[natoverse]

You are likely using a model that does not, in fast, support the response_format parameter. We've removed this validation so it should pass that error, but you may have mixed results with models that don't reliably support JSON responses.