Add fallback to full test (#7933)
The recent attempts of the night full test [kept
failing](https://github.com/deepspeedai/DeepSpeed/actions/workflows/aws-torch-latest-full.yml).
We added a fallback to an A100 node on the infra side.
This PR detects the CUDA architecture and number of GPUs and sets them
to env vars.
Signed-off-by: Masahiro Tanaka <mtanaka@anyscale.com>
