[numpy] mvlgamma: int -> float promotion (#59934)
Summary:
Reference: https://github.com/pytorch/pytorch/issues/42515
Last int->float promotion as per the tracker!
Pull Request resolved: https://github.com/pytorch/pytorch/pull/59934
Reviewed By: H-Huang
Differential Revision: D29160008
Pulled By: mruberry
fbshipit-source-id: 389a5a7683e0c00d474da913012768bf2a212ef0
