[check.yml] Disable MacOS action, pending investigation

Author: tkoeppe

.github/workflows/check.yml

@@ -18,7 +18,7 @@ jobs:
       matrix:
         cfg:
           - { name: 'Linux', os: 'ubuntu-24.04' }
-          - { name: 'MacOS', os: 'macos-15' }
+          # - { name: 'MacOS', os: 'macos-15' }
 
     steps:
       - name: checkout