Update OSX runners to macos-13

Author: oscarbenjamin

.github/workflows/buildwheel.yml

@@ -10,7 +10,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        os: [ubuntu-20.04, windows-2019, macos-12]
+        os: [ubuntu-20.04, windows-2019, macos-13]
 
     steps:
       - uses: actions/checkout@v4
@@ -108,7 +108,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        os: [ubuntu-20.04, windows-2019, macos-12]
+        os: [ubuntu-20.04, windows-2019, macos-13]
         python-version: ['3.9', '3.10', '3.11', '3.12']
 
     steps: