ci: switch macos-12 -> 13, add py13 (#48)

Author: wpbonelli

.github/workflows/ci.yml

@@ -60,8 +60,8 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        os: [ ubuntu-22.04, macos-12, windows-2022 ]
-        python: [ "310", "311", "312" ]
+        os: [ ubuntu-22.04, macos-13, windows-2022 ]
+        python: [ "310", "311", "312", "313" ]
     env:
       GCC_V: 11
     steps: