src: remove dead inspector code

This was overlooked in c5832453.

Refs: https://github.com/nodejs/node/pull/26137

PR-URL: https://github.com/nodejs/node/pull/26295


Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Tobias Nießen <tniessen@tnie.de>