Creating dedicated MacOS building machine

As a result of the Malware-Post-mortem we want to create a dedicated Build-machine for the MacOS build.

This is the issue to track that.

The issue names no files, tests, or entry points; begin by reviewing the Malware-Post-mortem referenced in the description and the repository's existing MacOS build process. Done would require a dedicated MacOS build machine and a documented way to use it, but the issue does not define the machine's requirements or setup steps.

Written by the indexing model from the issue text.