fix: pin python version to 3.13 in workflows (#933)

Lets try that again #931

Author: SoWieMarkus

.github/renovate.json

@@ -128,6 +128,11 @@
       "matchPackageNames": ["python"],
       "allowedVersions": "3.13.x"
     },
+    {
+      "matchManagers": ["github-actions"],
+      "matchPackageNames": ["actions/setup-python"],
+      "allowedVersions": "3.13.x"
+    },
     {
       "matchFileNames": [".github/actions/setup-claude-code-action/action.yml"],
       "automerge": false

.github/workflows/helm-lint.yaml

@@ -25,7 +25,7 @@ jobs:
 
       - uses: actions/setup-python@v6.2.0
         with:
-          python-version: "3.14"
+          python-version: "3.13"
           check-latest: true
 
       - name: Set up chart linting