remove nest_asyncio to fix deployment issue

app.py

@@ -10,11 +10,10 @@ from langchain.prompts import PromptTemplate
 from langchain_core.runnables import RunnablePassthrough
 from langchain_core.output_parsers import StrOutputParser
 import tempfile
-import nest_asyncio
 
 
 # Apply nest_asyncio
-nest_asyncio.apply()
+# nest_asyncio.apply()
 
 
 # Constants