fix pip: split torch index-url from main packages

Dockerfile

@@ -7,10 +7,13 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
 RUN pip install --no-cache-dir \
     fastapi uvicorn pydantic \
     numpy pandas scipy networkx scikit-learn \
-    torch --index-url https://download.pytorch.org/whl/cpu \
     transformers \
     matplotlib pillow requests beautifulsoup4
 
+RUN pip install --no-cache-dir \
+    --index-url https://download.pytorch.org/whl/cpu \
+    torch
+
 WORKDIR /app
 COPY server.py .