domain: remove `.dispose()`

`domain.dispose()` is generally considered an anti-pattern, has been
runtime-deprecated for over 4 years, and is a part of the `domain`
module that can not be emulated by `async_hooks`; so remove it.

Ref: https://nodejs.org/en/docs/guides/domain-postmortem/
Ref: 4a74fc97

PR-URL: https://github.com/nodejs/node/pull/15412


Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Trevor Norris <trev.norris@gmail.com>
Reviewed-By: Franziska Hinkelmann <franziska.hinkelmann@gmail.com>
Reviewed-By: Jeremiah Senkpiel <fishrock123@rocketmail.com>