add curl to Docker image

Dockerfile

@@ -4,6 +4,8 @@ WORKDIR /rembg
 
 RUN pip install --upgrade pip
 
+RUN apt-get update && apt-get install -y curl && apt-get clean && rm -rf /var/lib/apt/lists/*
+
 COPY . .
 
 RUN python -m pip install ".[cpu,cli]"