[numpy] `torch.cosh`: promote integer inputs to float (#48923)
Summary:
Reference: https://github.com/pytorch/pytorch/issues/42515
Pull Request resolved: https://github.com/pytorch/pytorch/pull/48923
Reviewed By: zhangguanheng66
Differential Revision: D25393679
Pulled By: mruberry
fbshipit-source-id: 2151ee0467b50175f84ac492c219a46ef6bd66c3
