test(system.rb): add support for mac_os_x [skip ci]

* Automated using myii/ssf-formula#442

Author: myii

test/integration/share/inspec.yml

@@ -21,4 +21,5 @@ supports:
   - platform-name: gentoo
   - platform-name: almalinux
   - platform-name: rocky
+  - platform-name: mac_os_x
   - platform: windows

test/integration/share/libraries/system.rb

@@ -57,6 +57,8 @@ def build_platform_release
       'base-latest'
     when 'gentoo'
       "#{inspec.platform[:release].split('.')[0]}-#{derive_gentoo_init_system}"
+    when 'mac_os_x'
+      inspec.command('sw_vers -productVersion').stdout.to_s
     when 'opensuse'
       # rubocop:disable Style/NumericLiterals,Layout/LineLength
       inspec.platform[:release].to_i > 20210101 ? 'tumbleweed' : inspec.platform[:release]