withStructuredOutput does not accept tools

[TiagoGouvea]

When using withStructuredOutput, the tools bind to the llm are ignored.

If we add a tools to the structured schema as a workaround it almost never works as expected.

On the invoke method, if it's a withStructuredOutput it will declare just one tool, to force the model to call a parser method to the response.

  const llm = new ChatOpenAI({ modelName: 'gpt-4o-mini' });
  llm.bindTools(tools}; // these tools will be ignored
  const llmResult = await llm
    .withStructuredOutput(outputSchema, { name: 'Response' })
    .invoke(messages);

Could be a way to use withStructuredOutput with custom tools as well.