Update upgrade command, add RELEASE notes

[iameskild]

Reference Issues or PRs

When I was testing 2023.5.1rc1 by upgrading an existing Nebari cluster, I ran into an issue where the deployment failed and complained about an existing service account:

[terraform]: │ Error: serviceaccounts "argo-admin" already exists
[terraform]: │
[terraform]: │   with module.argo-workflows[0].kubernetes_service_account_v1.argo-admin-sa,
[terraform]: │   on modules/kubernetes/services/argo-workflows/main.tf line 150, in resource "kubernetes_service_account_v1" "argo-admin-sa":
[terraform]: │  150: resource "kubernetes_service_account_v1" "argo-admin-sa" {
[terraform]: │
[terraform]: ╵

Although I was able to redeploy and get around this issue, I think it would be safer to have users delete the existing service accounts before deploying. Given that we are already requiring them to delete the CRDs, this adds a minimal additional step.

What does this implement/fix?

Put a x in the boxes that apply

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds a feature)
• Breaking change (fix or feature that would cause existing features not to work as expected)
• Documentation Update
• Code style update (formatting, renaming)
• Refactoring (no functional changes, no API changes)
• Build related changes
• Other (please describe):

Testing

• Did you test the pull request locally?
• Did you add new tests?

Any other comments?