replace deprecated workflow runner

Author: rwedge

.github/workflows/minimum.yml

@@ -14,7 +14,7 @@ jobs:
         python-version: ['3.9', '3.10', '3.11', '3.12', '3.13']
         os: [ubuntu-latest, windows-latest]
         include:
-          - os: macos-13
+          - os: macos-15-intel
             python-version: '3.9'
           - os: macos-latest
             python-version: '3.13'