Shift latest to 3.13 also

Author: rowleya

.github/workflows/python_checks.yml

@@ -266,15 +266,15 @@ jobs:
       matrix:
         include:
           - runner: windows-latest
-            python-version: "3.12"
+            python-version: "3.13"
             checks: 'tests'
 
           - runner: windows-2019
             python-version: 3.9
             checks: 'tests'
 
           - runner: macos-latest
-            python-version: "3.12"
+            python-version: "3.13"
             checks: 'tests'
 
           - runner: macos-12