util: set `super_` property to non-enumerable

Using `util.inherits()` adds a `super_` property to the constructor
and inspecting that constructor is going to show that property even
though it's not useful for the user.

Therefore the property is now set as non-enumerable and such entries
are not visible by default when using `console.log()` or
`util.inspect()`.

PR-URL: https://github.com/nodejs/node/pull/23107


Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Jeremiah Senkpiel <fishrock123@rocketmail.com>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>