neg_sparse: Fix output dtype (#68885)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/68885
`torch.neg` should preserve the input dtype but for sparse tensors it
was promoting integers to floating point. This would have been picked
up by the OpInfo-based test, but `neg` wasn't marked with
`supports_sparse=True` so it was never run.
cc nikitaved pearu cpuhrsch IvanYashchuk
Test Plan: Imported from OSS
Reviewed By: mrshenli
Differential Revision: D32680008
Pulled By: cpuhrsch
fbshipit-source-id: 502f8743c1c33ab802e3d9d097792887352cd220
