fix demo

examples/lightrag_nvidia_demo.py

@@ -125,7 +125,7 @@ async def initialize_rag():
 async def main():
     try:
         # Initialize RAG instance
-        rag = asyncio.run(initialize_rag())
+        rag = await initialize_rag()
 
         # reading file
         with open("./book.txt", "r", encoding="utf-8") as f: