ci: add lint ci for helm chart.

Signed-off-by: Lan Liang <gcslyp@gmail.com>

.github/workflows/lint-chart.yaml

@@ -0,0 +1,79 @@
+# validate any chart changes under charts directory
+name: Chart Lint
+
+env:
+  HELM_VERSION: v3.11.2
+  KIND_VERSION: v0.23.0
+  KIND_NODE_IMAGE: kindest/node:v1.30.0
+  K8S_VERSION: v1.30.0
+
+on:
+  push:
+    # Exclude branches created by Dependabot to avoid triggering current workflow
+    # for PRs initiated by Dependabot.
+    branches-ignore:
+      - 'dependabot/**'
+  pull_request:
+    paths:
+      - "charts/**"
+
+permissions:
+  contents: read
+
+jobs:
+  chart-lint-test:
+    runs-on: ubuntu-22.04
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+
+      - name: Set up Helm
+        uses: azure/setup-helm@v4
+        with:
+          version: ${{ env.HELM_VERSION }}
+
+      - name: Run chart-testing (template)
+        run: |
+          helm template --dependency-update ./kwok/charts --debug > /dev/null   
+
+      # Python is required because `ct lint` runs Yamale (https://github.com/23andMe/Yamale) and
+      # yamllint (https://github.com/adrienverge/yamllint) which require Python
+      - name: Set up Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: 3.9
+          check-latest: true
+
+      - name: Set up chart-testing
+        uses: helm/chart-testing-action@v2.6.1
+
+      - name: Add dependency chart repos
+        run: |
+          helm repo add bitnami https://charts.bitnami.com/bitnami
+
+      - name: Run chart-testing (list-changed)
+        id: list-changed
+        run: |
+          changed=$( ct list-changed )
+          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 --debug --check-version-increment=false
+
+      - name: Create kind cluster
+        uses: helm/kind-action@v1.10.0
+        if: steps.list-changed.outputs.changed == 'true'
+        with:
+          wait: 120s
+          version: ${{ env.KIND_VERSION }}
+          node_image: ${{ env.KIND_NODE_IMAGE }}
+          kubectl_version: ${{ env.K8S_VERSION }}
+
+      - name: Run chart-testing (install)
+        if: steps.list-changed.outputs.changed == 'true'
+        run: ct install --debug --helm-extra-args "--timeout 800s"