github: Add chart lint and test action.

Author: alexmv

.github/workflows/helm-test.yaml

@@ -0,0 +1,49 @@
+---
+name: Helm lint and test
+
+on:
+  pull_request:
+    branches:
+      - main
+
+jobs:
+  lint-test:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v5
+        with:
+          fetch-depth: 0
+
+      - name: Set up Helm
+        uses: azure/setup-helm@v4.2.0
+        with:
+          version: v3.17.0
+
+      - uses: actions/setup-python@v5.3.0
+        with:
+          python-version: "3.x"
+          check-latest: true
+
+      - name: Set up chart-testing
+        uses: helm/chart-testing-action@v2.7.0
+
+      - name: Run chart-testing (list-changed)
+        id: list-changed
+        run: |
+          changed=$(ct list-changed --chart-dirs kubernetes/chart --target-branch ${{ github.event.repository.default_branch }})
+          if [[ -n "$changed" ]]; then
+            echo "changed=true" >> "$GITHUB_OUTPUT"
+          fi
+
+      - name: Run chart-testing (lint)
+        if: steps.list-changed.outputs.changed == 'true'
+        run: ct lint --chart-dirs kubernetes/chart --target-branch ${{ github.event.repository.default_branch }}
+
+      - name: Create kind cluster
+        if: steps.list-changed.outputs.changed == 'true'
+        uses: helm/kind-action@v1.12.0
+
+      - name: Run chart-testing (install)
+        if: steps.list-changed.outputs.changed == 'true'
+        run: ct install --chart-dirs kubernetes/chart --target-branch ${{ github.event.repository.default_branch }}