Update dependency helm to v4

Author: renovate[bot]

.github/workflows/chart-testing.yaml

@@ -18,7 +18,7 @@ jobs:
       - name: Set up Helm
         uses: azure/setup-helm@v5
         with:
-          version: v3.12.1
+          version: v4.2.3
 
       - uses: actions/setup-python@v6
         with: