To fix inconsistency of digamma with SciPy (#56689)
Summary:
Fixes {https://github.com/pytorch/pytorch/issues/49015}
Pull Request resolved: https://github.com/pytorch/pytorch/pull/56689
Reviewed By: mruberry
Differential Revision: D28014563
Pulled By: iramazanli
fbshipit-source-id: 4d311e6a32737e44ebfabfc1a4b9414b0de7b46e
