Update actions/setup-python action to v5

Author: renovate[bot]

.github/workflows/publish-chart.yaml

@@ -27,7 +27,7 @@ jobs:
           version: ${{ env.HELM_VERSION }}
 
       # python is a requirement for the chart-testing action below (supports yamllint among other tests)
-      - uses: actions/setup-python@v4
+      - uses: actions/setup-python@v5
         with:
           python-version: 3.7