Automate helm charts update on each release

[mariomac]

We often forget to update our own helm chart. On each release, we should:
1- Create a PR towards main that updates the helm chart version and appVersion.
2- After our own helm chart is released, bump too the version in https://github.com/grafana/beyla/actions/workflows/helm-release.yml

Or, at least, if the helm chart is not updated, having some red badge in the repo that would remind us to do it.