Access to tool calls and tool outputs in post_run_hook

[salman1993]

Usage example:

class CustomAssistant(Assistant):
    def post_run_hook(self, run: "Run", tool_calls, tool_outputs):
        print(f"\n\nPost run hook")
        print(f"tool_calls: {tool_calls}")
        print(f"tool_outputs: {tool_outputs}")

ai = CustomAssistant(
    name="CustomAssistant",
    instructions="You are a helpful assistant."
)