chore(deps): update helm/chart-testing-action action to v2.8.0 (#727)

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

@@ -29,7 +29,7 @@ jobs:
           helm repo add matrix-authentication-service https://small-hack.github.io/matrix-authentication-service-chart
 
       - 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