doc,test: fix inspect's sorted compare function

In V8 7.0, the array sorting algorithm was changed to Timsort, which
is stable. A compare function returning only `true` or `false`
(converted to 0 and 1) cannot work properly.

PR-URL: https://github.com/nodejs/node/pull/22992


Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Kyle Farnung <kfarnung@microsoft.com>