Fix `TestSparse.test_bmm_windows_error` when CUDA is not available (#42626)
Summary:
Refactor comnon pattern of (torch.cuda.version and [int(x) for x in torch.cuda.version.split(".")] >= [a, b]) into `_get_torch_cuda_version()` function
Pull Request resolved: https://github.com/pytorch/pytorch/pull/42626
Reviewed By: seemethere
Differential Revision: D22956149
Pulled By: malfet
fbshipit-source-id: 897c55965e53b477cd20f69e8da15d90489035de
