Use chart-releaser-action tag v1.6.0 (#3429)

Context:
#3427 (comment)

Try tagged version of chart-releaser-action now that mark_latest option
is available

### Pull Request Checklist

<!-- Please read
https://matrix-org.github.io/dendrite/development/contributing before
submitting your pull request -->

* [x] I have added Go unit tests or [Complement integration
tests](https://github.com/matrix-org/complement) for this PR _or_ I have
justified why this PR doesn't need tests
* [x] Pull request includes a [sign off below using a legally
identifiable
name](https://matrix-org.github.io/dendrite/development/contributing#sign-off)
_or_ I have already signed off privately

Signed-off-by: `Rhea Danzey <rdanzey@element.io>`

.github/workflows/helm.yml

@@ -32,7 +32,7 @@ jobs:
           version: v3.10.0
 
       - name: Run chart-releaser
-        uses: helm/chart-releaser-action@ed43eb303604cbc0eeec8390544f7748dc6c790d # specific commit, since `mark_as_latest` is not yet in a release
+        uses: helm/chart-releaser-action@v1.6.0
         env:
           CR_TOKEN: "${{ secrets.GITHUB_TOKEN }}"
         with: