Add handling of pydantic state object in ToolNode class

[geet000]

When I use pydantic state and ToolNode, I get following error.

langgraph\prebuilt\tool_node.py", line 143, in _parse_input
elif messages := input.get("messages", []):
^^^^^^^^^
AttributeError: 'MyState' object has no attribute 'get'

Can we add support for pydantic state object in ToolNode class?
Thanks

[abprime]

This PR #1608 adds support for pydantic v1 based states.

Please take a look and suggest any changes.

[nfcampos]

Hi, this has been added.