Update actions/setup-python action to v6

Author: renovate[bot]

.github/workflows/pythonapp.yml

@@ -15,7 +15,7 @@ jobs:
 
     steps:
       - uses: actions/checkout@v4
-      - uses: actions/setup-python@v5
+      - uses: actions/setup-python@v6
         with:
           python-version: "3.10"
           cache: "pip" # caching pip dependencies