chore(deps): bump helm/chart-testing-action from 2.1.0 to 2.3.1

Bumps [helm/chart-testing-action](https://github.com/helm/chart-testing-action) from 2.1.0 to 2.3.1.
- [Release notes](https://github.com/helm/chart-testing-action/releases)
- [Commits](helm/chart-testing-action@v2.1.0...v2.3.1)

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

Signed-off-by: dependabot[bot] <[email protected]>

.github/workflows/docker-image.yml

@@ -64,7 +64,7 @@ jobs:
         with:
           python-version: 3.7
       - name: Set up chart-testing (for Helm)
-        uses: helm/chart-testing-action@v2.1.0
+        uses: helm/chart-testing-action@v2.3.1
       - name: lint helm chart
         run: |
           cd ./charts/koozie-exporter