Bump the github-actions-update group with 1 update

Bumps the github-actions-update group with 1 update: [helm/chart-testing-action](https://github.com/helm/chart-testing-action).

- [Release notes](https://github.com/helm/chart-testing-action/releases)
- [Commits](helm/chart-testing-action@v2.4.0...v2.6.0)

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

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

.github/workflows/helm.yaml

@@ -22,7 +22,7 @@ jobs:
           go-version-file: "go.mod"
 
       - name: "Set up chart-testing"
-        uses: helm/chart-testing-action@v2.4.0
+        uses: helm/chart-testing-action@v2.6.0
 
       - name: "Run chart-testing (lint)"
         run: ct lint --config ct.yaml