test: check noop invocation with mustNotCall()

In test-child-process-spawnsync-validation-errors, check that functions
used inappropriately as options are not invoked.

PR-URL: https://github.com/nodejs/node/pull/13205


Reviewed-By: Refael Ackermann <refack@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Richard Lau <riclau@uk.ibm.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>