[Bug]: `DataPart` should accept objects as data, not just dicts.

[gspencergoog]

What happened?

According to the A2A spec's proto file, the DataPart accepts any object, not just maps, whereas the Python implementation specifically only allows dicts.

Perhaps the Python implementation is still in the process of adopting the updated proto?

[Akshat8510]

Hi @gspencergoog, I’d like to work on this.

Proposed Solution:
I will update the DataPart model to expand the data field's type hint from dict to a broader type (likely Any or a Union of valid types) to align with the A2A specification. I’ll also verify that the serialization logic (JSON/Proto) correctly handles arrays and primitive objects, and I'll add unit tests to cover these new cases.

[Akshat8510]

Please assign this to me