fix run command

Signed-off-by: Sun Ruoxi <sunruoxi@4paradigm.com>

Dockerfile

@@ -4,7 +4,9 @@ WORKDIR /workspace
 
 # 复制 requirements.txt 并安装 Python 依赖
 COPY requirements.txt .
-RUN pip install --no-cache-dir -r requirements.txt
+RUN apt update
+RUN apt install python3-pip
+RUN pip3 install --no-cache-dir -r requirements.txt
 
 # 复制 server.py 到 workspace
 COPY server.py /workspace/