Update requirements.txt

backend/requirements.txt

@@ -16,6 +16,10 @@ aiohttp
 peewee
 bcrypt
 
+torch --index-url https://download.pytorch.org/whl/cpu
+torchvision --index-url https://download.pytorch.org/whl/cpu
+torchaudio --index-url https://download.pytorch.org/whl/cpu
+
 langchain
 langchain-community
 chromadb