Use only macos-latest (=macos-14)

Author: Ko Nagase

.github/workflows/macos.yml

@@ -46,7 +46,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        os: [macos-latest, macos-14]
+        os: [macos-latest]
 
     steps:
       - name: Checkout repository