Point Helm v2 at "new" stable

What does this MR do?

Point Helm v2 (helm init) at "new" stable, via --stable-repo-url set to https://charts.helm.sh/stable

This is due to forced deprecation of the old location & charts

1. Error: error unpacking deprecation-0.2.2.tgz in gitlab: apiVersion 'v2' is not valid. The value must be "v1"

2. ...Unable to get an update from the "stable" chart repository (https://kubernetes-charts.storage.googleapis.com):
           failed to fetch https://kubernetes-charts.storage.googleapis.com/index.yaml : 403 Forbidden

Checklist

See Definition of done.

For anything in this list which will not be completed, please provide a reason in the MR discussion.

Required

• Merge Request Title and Description are up to date, accurate, and descriptive
• MR targeting the appropriate branch
• MR has a green pipeline on GitLab.com

Expected (please provide an explanation if not completing)

• Test plan indicating conditions for success has been posted and passes
• Documentation created/updated
• Tests added