Update actions/setup-python action to v6

Author: renovate[bot]

.github/workflows/yamllint.yml

@@ -18,7 +18,7 @@ jobs:
         uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
 
       - name: Set up Python
-        uses: actions/setup-python@v4
+        uses: actions/setup-python@v6
         with:
           python-version: 3.14