doc: add warning to assert.doesNotThrow()

Using `assert.doesNotThrow()` has no benefit over adding a comment
next to some code that should not throw. Therefore it is from now
on discouraged to use it.

PR-URL: https://github.com/nodejs/node/pull/18699


Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Gibson Fahnestock <gibfahn@gmail.com>
Reviewed-By: Tiancheng "Timothy" Gu <timothygu99@gmail.com>
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Sakthipriyan Vairamani <thechargingvolcano@gmail.com>