fix(magentic-one): Enhance error handling in orchestrate_step to manage invalid ledger formats

[r-bit-rry]

lets

Why are these changes needed?

fix the selected code, progress_ledger[key] might not be a string, it can also be Boolean or integer or whatever, in that case we will get a TypeError and except out of the loop, instead it should be handled as part of the handling of key_error in the selected code

Related issue number

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[afourney]

Thanks. This looks good to me and catches a reasonable error case.

We weren't seeing this often on our end. Would you mind sharing which version of which model you are using?

(In any case, this is a good error to catch)

[r-bit-rry]

I'm fiddling with local models, mostly Llama3.2-vision served through ollama.
Since both ollama and azure/openai API support structured output, and receiving output schema. maybe we should move to pydantic BaseModel and declare the ledge and other classes/object that we would like to receive in a structured way, can maybe even save tokens in the prompts and retry attempts:
https://ollama.com/blog/structured-outputs
https://learn.microsoft.com/en-us/azure/ai-services/openai/how-to/structured-outputs?tabs=python-secure