Update helm/chart-testing-action action to v2.8.0 (#101)

Co-authored-by: small-hack-renovate[bot] <151926327+small-hack-renovate[bot]@users.noreply.github.com>

Author: small-hack-renovate[bot]

.github/workflows/ci-helm-lint-test.yml

@@ -28,7 +28,7 @@ jobs:
           helm repo add bitnami https://charts.bitnami.com/bitnami
 
       - name: Set up chart-testing
-        uses: helm/chart-testing-action@v2.7.0
+        uses: helm/chart-testing-action@v2.8.0
 
       - name: Run chart-testing (list-changed)
         id: list-changed
@@ -63,7 +63,7 @@ jobs:
           helm repo add bitnami https://charts.bitnami.com/bitnami
 
       - name: Set up chart-testing
-        uses: helm/chart-testing-action@v2.7.0
+        uses: helm/chart-testing-action@v2.8.0
 
       - name: Run chart-testing (list-changed)
         id: list-changed