add lint-helm workflow

Signed-off-by: Simon L <szaimen@e.mail.de>

.github/workflows/lint-helm.yml

@@ -0,0 +1,46 @@
+name: Lint and Test Charts
+
+on:
+  workflow_dispatch:
+  pull_request:
+    paths:
+      - 'nextcloud-aio-helm-chart/**'
+
+jobs:
+  lint-helm:
+    runs-on: ubuntu-22.04
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v3
+        with:
+          fetch-depth: 0
+
+      - name: Install Helm
+        uses: azure/setup-helm@v3.5
+        with:
+          version: v3.11.1
+
+      - name: Set up chart-testing
+        uses: helm/chart-testing-action@v2.4.0
+
+      - name: Run chart-testing (list-changed)
+        id: list-changed
+        run: |
+          changed=$(ct list-changed --target-branch ${{ github.event.repository.default_branch }})
+          if [[ -n "$changed" ]]; then
+            echo "changed=true" >> "$GITHUB_OUTPUT"
+          fi
+
+      - name: Run chart-testing (lint)
+        id: lint
+        if: steps.list-changed.outputs.changed == 'true'
+        run: ct lint --target-branch ${{ github.event.repository.default_branch }}
+
+      - name: Create kind cluster
+        uses: helm/kind-action@v1.8.0
+        if: steps.list-changed.outputs.changed == 'true'
+
+      - name: Run chart-testing (install)
+        id: install
+        if: steps.list-changed.outputs.changed == 'true'
+        run: ct install --target-branch ${{ github.event.repository.default_branch }}