Update Dockerfile

Dockerfile

@@ -2,8 +2,8 @@
 FROM pytorch/pytorch:1.9.0-cuda11.1-cudnn8-devel
 
 # Add NVIDIA CUDA GPG key
-RUN apt-key adv --fetch-keys https://developer.download.nvidia.com/compute/cuda/repos/ubuntu1804/x86_64/7fa2af80.pub
-
+# Add NVIDIA CUDA GPG key using a different key server
+RUN apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv-key A4B469963BF863CC
 
 # Install Git and system libraries required for OpenGL without interactive prompts
 ENV DEBIAN_FRONTEND=noninteractive