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

Author: renovate[bot]

.github/workflows/pr-build.yaml

@@ -32,7 +32,7 @@ jobs:
           python-version: 3.13
 
       - 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
@@ -204,7 +204,7 @@ jobs:
           python-version: 3.13
 
       - 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@a1b0e391336a6ee6713a0583f8c6240d70863de3 # v1.12.0