langchain_openai: Add "strict" parameter to OpenAIFunctionsAgent (#25862)

- **Description:** OpenAI recently introduced a "strict" parameter for
[structured outputs in their
API](https://openai.com/index/introducing-structured-outputs-in-the-api/).
An optional `strict` parameter has been added to
`create_openai_functions_agent()` and `create_openai_tools_agent()` so
developers can use this feature in those agents.

---------

Co-authored-by: Chester Curme <chester.curme@gmail.com>

libs/langchain/langchain/agents/openai_tools/base.py

@@ -1,4 +1,4 @@
-from typing import Sequence
+from typing import Optional, Sequence
 
 from langchain_core.language_models import BaseLanguageModel
 from langchain_core.prompts.chat import ChatPromptTemplate
@@ -13,7 +13,10 @@ from langchain.agents.output_parsers.openai_tools import OpenAIToolsAgentOutputP
 
 
 def create_openai_tools_agent(
-    llm: BaseLanguageModel, tools: Sequence[BaseTool], prompt: ChatPromptTemplate
+    llm: BaseLanguageModel,
+    tools: Sequence[BaseTool],
+    prompt: ChatPromptTemplate,
+    strict: Optional[bool] = None,
 ) -> Runnable:
     """Create an agent that uses OpenAI tools.
 
@@ -87,7 +90,9 @@ def create_openai_tools_agent(
     if missing_vars:
         raise ValueError(f"Prompt missing required variables: {missing_vars}")
 
-    llm_with_tools = llm.bind(tools=[convert_to_openai_tool(tool) for tool in tools])
+    llm_with_tools = llm.bind(
+        tools=[convert_to_openai_tool(tool, strict=strict) for tool in tools]
+    )
 
     agent = (
         RunnablePassthrough.assign(