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

Checks

• I've included any doc changes needed for https://microsoft.github.io/autogen/. See https://microsoft.github.io/autogen/docs/Contribute#documentation to build and test documentation locally.
• [] I've added tests (if relevant) corresponding to the changes introduced in this PR.
• I've made sure all auto checks have passed.