parallalization issue with telemetry context manager

[dumbPy]

The recently introduced telemetry context managers in #31 by @holtskinner causes issue with parallelisation.

Given that the generation is an io task, concurrency is a crucial aspect that cannot be overlooked.

If multiple models are awaited in parallel, they all seem to append to same list causing exception on exit

here's an reproducible example

from langchain_google_vertexai import ChatVertexAI
from langchain_core.prompts import ChatPromptTemplate
import asyncio

model1 = ChatVertexAI(model_name="chat-bison@002")
model2 = ChatVertexAI(model_name="gemini-1.0-pro")

chain1 = ChatPromptTemplate.from_messages(["Why is the sky blue?"]) | model1

chain2 = ChatPromptTemplate.from_messages(["Why is the sky blue?"]) | model2

async def main():
    async with asyncio.TaskGroup() as tg:
        tg.create_task(chain1.ainvoke({}))
        tg.create_task(chain2.ainvoke({}))

asyncio.run(main())

Exception:

 | Traceback (most recent call last):
    |   File "/Users/sufiyan/micromamba/envs/nlp-cloud-server/lib/python3.11/site-packages/langchain_core/runnables/base.py", line 2536, in ainvoke
    |     input = await step.ainvoke(
    |             ^^^^^^^^^^^^^^^^^^^
    |   File "/Users/sufiyan/micromamba/envs/nlp-cloud-server/lib/python3.11/site-packages/langchain_core/language_models/chat_models.py", line 179, in ainvoke
    |     llm_result = await self.agenerate_prompt(
    |                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |   File "/Users/sufiyan/micromamba/envs/nlp-cloud-server/lib/python3.11/site-packages/langchain_core/language_models/chat_models.py", line 570, in agenerate_prompt
    |     return await self.agenerate(
    |            ^^^^^^^^^^^^^^^^^^^^^
    |   File "/Users/sufiyan/micromamba/envs/nlp-cloud-server/lib/python3.11/site-packages/langchain_core/language_models/chat_models.py", line 530, in agenerate
    |     raise exceptions[0]
    |   File "/Users/sufiyan/micromamba/envs/nlp-cloud-server/lib/python3.11/site-packages/langchain_core/language_models/chat_models.py", line 715, in _agenerate_with_cache
    |     result = await self._agenerate(
    |              ^^^^^^^^^^^^^^^^^^^^^^
    |   File "/Users/sufiyan/micromamba/envs/nlp-cloud-server/lib/python3.11/site-packages/langchain_google_vertexai/chat_models.py", line 635, in _agenerate
    |     with telemetry.tool_context_manager(self._user_agent):
    |   File "/Users/sufiyan/micromamba/envs/nlp-cloud-server/lib/python3.11/contextlib.py", line 144, in __exit__
    |     next(self.gen)
    |   File "/Users/sufiyan/micromamba/envs/nlp-cloud-server/lib/python3.11/site-packages/google/cloud/aiplatform/telemetry.py", line 48, in tool_context_manager
    |     _pop_tool_name(tool_name)
    |   File "/Users/sufiyan/micromamba/envs/nlp-cloud-server/lib/python3.11/site-packages/google/cloud/aiplatform/telemetry.py", line 57, in _pop_tool_name
    |     raise RuntimeError(
    | RuntimeError: Tool context error detected. This can occur due to parallelization.
    +------------------------------------

[lkuligin]

can you try the version from main, please? it works without an error on my side.