Update python-ci.yaml (#435)

Author: mpiannucci

.github/workflows/python-ci.yaml

@@ -135,7 +135,7 @@ jobs:
     strategy:
       matrix:
         platform:
-          - runner: macos-12
+          - runner: macos-13
             target: x86_64
           - runner: macos-14
             target: aarch64