Publish Helm releases in non-oci format

[theSuess]

Is your feature request related to a problem? Please describe.
Some users expect helm releases to be available in non-oci format. This is especially relevant for large enterprises which require mirroring of helm charts.

Describe the solution you'd like
Publish the grafana-operator helm chart to https://github.com/grafana/helm-charts/

Additional context
https://github.com/apps/grafana-operator-helm-release already exists with the correct permissions to publish in the helm-charts repository

Existing solutions
https://github.com/grafana/k6-operator/blob/main/.github/workflows/helm-release.yaml

[weisdd]

Implemented by @theSuess