Update return type Object.keys(o)

[Dima-Dim]

Object.keys(o) does not return an array of strings, but an array of keys o.

Fixes #

[DanielRosenwasser]

This is likely not doing what you think it is. First off, typeof will give you {} and keyof typeof {} will give you never. If you wanted to make it generic to have Object.keys return keyof T for a parameter type of T, this is a duplicate of #37495