fix(langchain_ibm): Support either reasoning_content or reasoning in ChatWatsonx.invoke response

[Karol Zmorski (KarolZm)]

📝 Description

Related Issue:

💡 Summary of Changes

• Added support for reasoning since either reasoning_content or reasoning may be included in the chat response when include_reasoning=True passed in parameters.
• Updated tests with reasoning.
• Updated tests for WatsonxToolkit and WatsonxTool because of API changes.

Example:

AIMessage(content='Hello! 👋 How can I assist you today?', additional_kwargs={'reasoning': 'We need to respond: "Hello!" maybe additional friendly greeting. Should be succinct.'}, response_metadata={'token_usage': {'completion_tokens': 38, 'prompt_tokens': 70, 'total_tokens': 108}, 'model_name': 'openai/gpt-oss-120b', 'system_fingerprint': '', 'finish_reason': 'stop'}, id='chatcmpl-4236eb085c28e2748b3add9d66a1cf7e', tool_calls=[], invalid_tool_calls=[], usage_metadata={'input_tokens': 70, 'output_tokens': 38, 'total_tokens': 108})

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✅ PR Checklist

• PR Title Format: {TYPE}({SCOPE}): {DESCRIPTION}

  • Examples:
    • feat(langchain-ibm): add multi-tenant support
    • fix(langchain-db2): resolve flag parsing error
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🧪 Testing (optional)

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🗒️ Notes (optional)

Thank you again for helping improve LangChain-IBM! 🚀
Your contribution makes the project better for everyone.

[Rafal-Chrzanowski-IBM]

LGTM

[Mateusz Szewczyk (mateusz-szewczyk-dev)]

LGTM