Bump helm/chart-testing-action from 2.7.0 to 2.8.0 (#1394)

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](helm/chart-testing-action@0d28d31...6ec842c)

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

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

Author: dependabot[bot]

.github/workflows/lint.yaml

@@ -52,7 +52,7 @@ jobs:
         uses: azure/setup-helm@b9e51907a09c216f16ebe8536097933489208112 # v4.3.0
 
       - 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 (lint)
         run: ct lint --charts charts/mondoo-operator --validate-maintainers=false