Use chart testing action v2.7.0 during install

Author: paapug

.github/workflows/bootzooka-helm-ci.yaml

@@ -23,12 +23,30 @@ jobs:
         with:
           fetch-depth: 0
 
-      - name: Run chart-testing (lint)
-        id: ct-lint
-        uses: helm/chart-testing-action@v2.7.0
+      - name: Set up Helm
+        uses: azure/setup-helm@v4.3.0
         with:
-          command: lint
-          config: .github/helm-ct.yml
+          version: v3.17.1
+
+      - 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 --config .github/helm-ct.yml --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 --config .github/helm-ct.yml --target-branch ${{ github.event.repository.default_branch }}
 
   install-test-chart:
     needs:
@@ -55,12 +73,30 @@ jobs:
           node_image: kindest/node:${{ matrix.k8s }}
           wait: "120s"
 
-      - name: Run chart-testing (install)
-        id: ct-install
-        uses: helm/chart-testing-action@v1.1.0
+      - name: Set up Helm
+        uses: azure/setup-helm@v4.3.0
+        with:
+          version: v3.17.1
+
+      - uses: actions/setup-python@v5.3.0
         with:
-          command: install
-          config: .github/helm-ct.yml
+          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 --config .github/helm-ct.yml --target-branch ${{ github.event.repository.default_branch }})
+          if [[ -n "$changed" ]]; then
+            echo "changed=true" >> "$GITHUB_OUTPUT"
+          fi
+
+      - name: Run chart-testing (install)
+        if: steps.list-changed.outputs.changed == 'true'
+        run: ct install --config .github/helm-ct.yml --target-branch ${{ github.event.repository.default_branch }}
 
   validate-chart-docs:
     needs: