use torch 1.9 (microsoft#2215)

.github/workflows/nv-accelerate-v100.yml

@@ -31,7 +31,7 @@ jobs:
           nvcc --version
           pip install --upgrade pip
           pip uninstall --yes torch torchvision
-          pip install torch==1.8.2+cu111 torchvision==0.9.2+cu111 -f https://download.pytorch.org/whl/lts/1.8/torch_lts.html
+          pip install torch==1.9.1+cu111 torchvision==0.10.1+cu111 -f https://download.pytorch.org/whl/torch_stable.html
           python -c "import torch; print('torch:', torch.__version__, torch)"
           python -c "import torch; print('CUDA available:', torch.cuda.is_available())"