community: Use Blockbuster to detect blocking calls in asyncio during tests (#29609)

Same as https://github.com/langchain-ai/langchain/pull/29043 for
langchain-community.

**Dependencies:**
- blockbuster (test)

**Twitter handle:** cbornet_

Co-authored-by: Erick Friis <erick@langchain.dev>

libs/community/langchain_community/utils/openai.py

@@ -1,10 +1,12 @@
 from __future__ import annotations
 
+import functools
 from importlib.metadata import version
 
 from packaging.version import parse
 
 
+@functools.cache
 def is_openai_v1() -> bool:
     """Return whether OpenAI API is v1 or more."""
     _version = parse(version("openai"))