upgrade base image to pytorch 21.09

[wyli]

Is your feature request related to a problem? Please describe.
CUDA_VERSION=11.4.2.006 CUDA_DRIVER_VERSION=470.57.02

[wyli]

the fast training test can't pass the test, I'll increase the time limit https://github.com/Project-MONAI/MONAI/runs/3904103140?check_suite_focus=true cc @Nic-Ma

[Nic-Ma]

OK, please add it in PyTorch 21.09 update.

Thanks.