Use CPU PyTorch base image for automatic Doubao service

Dockerfile

@@ -1,4 +1,4 @@
-FROM python:3.10-slim
+FROM pytorch/pytorch:2.3.1-cpu
 
 ENV PYTHONUNBUFFERED=1 \
     PIP_NO_CACHE_DIR=1 \
@@ -17,7 +17,6 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
 
 COPY requirements.txt .
 RUN pip install --upgrade pip \
-    && pip install torch --index-url https://download.pytorch.org/whl/cpu \
     && pip install -r requirements.txt
 
 COPY app.py doubao_alpha.png ./