test: skipIfInspectorDisabled cluster-inspect-brk

When configured --without-ssl the inspect-brk option will not be
available and the process will exit with a exit value of 9 "Invalid
Argument/Bad option".

This commit adds a skipIfInspectorDisabled check since --without-ssl
implies that no inspector support is build as well.

PR-URL: https://github.com/nodejs/node/pull/12757


Reviewed-By: Refael Ackermann <refack@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>