Minion cannot be managed on grain.os == 'MacOS' systems.

Current use of 'pkg.installed' statement fails if Brew is not available and/or Salt configured to interact with it properly. Brew based salt-minion is an inappropriate way of installing/managing salt now that official .pkg releases are available.

The following are the principle issues for swapping to .pkg based install/upgrade of minion:

1. Installed .pkg name is actually 'com.saltstack.salt'
2. True config path is '/private/etc/salt'
3. Service name is 'com.saltstack.salt.minion'
4. No current entry in os_family_map for 'MacOS' for salt-formula
5. .pkg needs to be downloaded
6. .pkg installation should occur using macpackage.installed (or cmd.run 'installer -pkg /path/to/salt.pkg -target /')

Reference info:
https://docs.saltstack.com/en/latest/topics/installation/osx.html
https://repo.saltstack.com/osx/
https://docs.saltstack.com/en/latest/ref/states/all/salt.states.mac_package.html