Build on macos-13 as well

Author: honnibal

.github/workflows/cibuildwheel.yml

@@ -14,7 +14,7 @@ jobs:
     strategy:
       matrix:
         # macos-13 is an intel runner, macos-14 is apple silicon
-        os: [macos-14]
+        os: [macos-13, macos-14]
 
     steps:
       - uses: actions/checkout@v4