Update actions/setup-python action to v6

Author: small-hack-renovate[bot]

.github/workflows/test-chart.yml

@@ -21,7 +21,7 @@ jobs:
 
     steps:
       - uses: actions/checkout@v5
-      - uses: actions/setup-python@v5
+      - uses: actions/setup-python@v6
         with:
           python-version: "3.x"