scripts: add MACHO NX check to security-check.py

Summary:
This is a backport of core#18415
https://github.com/bitcoin/bitcoin/pull/18415/commits/edaca2dd123cef958699c07ab248cf0ffc71af07

Depends on D13551

Test Plan: gitian build and run test-security-check.py on a Mac OS machine

Reviewers: #bitcoin_abc, Fabien

Reviewed By: #bitcoin_abc, Fabien

Subscribers: Fabien

Differential Revision: https://reviews.bitcoinabc.org/D13552