chore(deps): update helm/chart-testing-action action to v2.8.0 (#668)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

.github/workflows/helm-test.yaml

@@ -26,7 +26,7 @@ jobs:
         python-version: '3.14'
 
     - name: Set up chart-testing
-      uses: helm/chart-testing-action@0d28d3144d3a25ea2cc349d6e59901c4ff469b3b # v2.7.0
+      uses: helm/chart-testing-action@6ec842c01de15ebb84c8627d2744a0c2f2755c9f # v2.8.0
 
     - name: Run chart-testing (list-changed)
       id: list-changed
@@ -52,7 +52,7 @@ jobs:
         python-version: '3.14'
 
     - name: Set up chart-testing
-      uses: helm/chart-testing-action@0d28d3144d3a25ea2cc349d6e59901c4ff469b3b # v2.7.0
+      uses: helm/chart-testing-action@6ec842c01de15ebb84c8627d2744a0c2f2755c9f # v2.8.0
 
     - name: Create kind cluster
       uses: helm/kind-action@92086f6be054225fa813e0a4b13787fc9088faab # v1.13.0