add pytest-asyncio to tox.jinja

Author: shellmayr

scripts/populate_tox/tox.jinja

@@ -252,7 +252,9 @@ deps =
     langchain-{latest,notiktoken}: langchain
     langchain-{latest,notiktoken}: langchain-openai
     langchain-{latest,notiktoken}: openai>=1.6.1
+    langchain-{latest,notiktoken}: pytest-asyncio
     langchain-latest: tiktoken~=0.6.0
+    langchain-latest: pytest-asyncio
 
     # OpenAI
     openai: pytest-asyncio