chore(deps): update actions/setup-python action to v6

Author: renovate[bot]

.github/workflows/workflow.yml

@@ -35,7 +35,7 @@ jobs:
 
       # Python is required because `ct lint` runs Yamale (https://github.com/23andMe/Yamale) and
       # yamllint (https://github.com/adrienverge/yamllint) which require Python
-      - uses: actions/setup-python@v5
+      - uses: actions/setup-python@v6
         with:
           python-version: '3.13'
           check-latest: true