[numpy] `torch.{a}tanh` : promote integer inputs to float (#47064)
Summary:
Reference https://github.com/pytorch/pytorch/issues/42515
Pull Request resolved: https://github.com/pytorch/pytorch/pull/47064
Reviewed By: mrshenli
Differential Revision: D24681107
Pulled By: mruberry
fbshipit-source-id: 1818206c854dbce7074363bf6f1949daa7bf6052
