chore(deps): bump helm/chart-testing-action from 2.7.0 to 2.8.0 (#5565)

Bumps [helm/chart-testing-action](https://github.com/helm/chart-testing-action) from 2.7.0 to 2.8.0.
- [Release notes](https://github.com/helm/chart-testing-action/releases)
- [Commits](https://github.com/helm/chart-testing-action/compare/0d28d3144d3a25ea2cc349d6e59901c4ff469b3b...6ec842c01de15ebb84c8627d2744a0c2f2755c9f)

---
updated-dependencies:
- dependency-name: helm/chart-testing-action
  dependency-version: 2.8.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

.github/workflows/helm.yml

@@ -35,7 +35,7 @@ jobs:
           python-version: 3.12
 
       - 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