openai: `bind_tools` not callable after `with_structured_output`

### Checked other resources - [X] I added a very descriptive title to this issue. - [X] I searched the LangChain documentation with the integrated search. - [X] I used the GitHub search to find a similar question and didn't find it. - [X] I am sure that this is a bug in LangChain rather than my code. - [X] The bug is not resolved by updating to the latest stable version of LangChain (or the specific integration package). ### Example Code ``` from langchain_openai import ChatOpenAI from pydantic import BaseModel, Field from langchain.tools import StructuredTool class ResponseModel(BaseModel): a_value:str = Field(description="This doesn't matter much") def a_func(val: int): return True a_tool = StructuredTool.from_function( func=a_func, name="A func", description="A function you will need", ) llm = ChatOpenAI(model="gpt-4o-mini",temperature=0) structured_llm = llm.with_structured_output(ResponseModel) llm_with_tools = structured_llm.bind_tools([a_tool]) <----- not available ``` ### Error Message and Stack Trace (if applicable) 'RunnableSequence' object has no attribute 'bind_tools' ### Description I am attempting to retrieved structured output in a json format (to pass via an api to a frontend), and I also require calling out to tools. I cannot figure out how to combine the two, or there is an issue with code to do so. ### System Info System Information ------------------ > OS: Darwin > OS Version: Darwin Kernel Version 24.1.0: Thu Oct 10 21:02:27 PDT 2024; root:xnu-11215.41.3~2/RELEASE_X86_64 > Python Version: 3.13.1 (main, Dec 3 2024, 17:59:52) [Clang 16.0.0 (clang-1600.0.26.4)] Package Information ------------------- > langchain_core: 0.3.28 > langchain: 0.3.13 > langchain_community: 0.3.13 > langsmith: 0.2.4 > langchain_experimental: 0.3.4 > langchain_openai: 0.2.14 > langchain_text_splitters: 0.3.4 Optional packages not installed ------------------------------- > langserve Other Dependencies ------------------…