message: Switch default of TF Windows CI builds to CUDA 11.
  This is a no-op because we already set TF_CUDA_VERSION in scripts that call this, so it's merely to avoid confusion.
diff: @@ -55,8 +55,8 @@ export PATH="/c/Program Files/Git/cmd:$PATH"
  export PATH="/c/${PYTHON_BASE_PATH}/Scripts:$PATH"
  # Setting default values to CUDA related environment variables
  -export TF_CUDA_VERSION=${TF_CUDA_VERSION:-10.1}
  -export TF_CUDNN_VERSION=${TF_CUDNN_VERSION:-7}
  +export TF_CUDA_VERSION=${TF_CUDA_VERSION:-11.0}
  +export TF_CUDNN_VERSION=${TF_CUDNN_VERSION:-8}
  export TF_CUDA_COMPUTE_CAPABILITIES=${TF_CUDA_COMPUTE_CAPABILITIES:-6.0}
  export CUDA_TOOLKIT_PATH=${CUDA_TOOLKIT_PATH:-"C:/Program Files/NVIDIA GPU Computing Toolkit/CUDA/v${TF_CUDA_VERSION}"}
  export CUDNN_INSTALL_PATH=${CUDNN_INSTALL_PATH:-"C:/tools/cuda"}
  