Update actions/setup-python action to v6

Author: renovate[bot]

.github/workflows/ruff.yml

@@ -10,7 +10,7 @@ jobs:
           ref: ${{ github.event.pull_request.head.ref }}
 
       - name: Set up Python
-        uses: actions/setup-python@v5
+        uses: actions/setup-python@v6
         with:
           python-version: '3.13'