Migrate Redis settings to the new structure on k8s workload

The problem

The distribution team updated the Redis chart to use password in a new structure: gitlab-org/charts/gitlab!3140 (comment 1392630589)

The global.redis.password.[enabled,secret,key] values will still merge correctly, but the warnings will persist until they are renamed to global.redis.auth.[value]

What needs to be done

Graeme tested this and concluded that we need to migrate the settings after the chart bump so we don't break k8s-wokload: gitlab-org/charts/gitlab!3140 (comment 1393147279)

Milestones

• Chart bump with the new settings is ready to be merged
  • Merge the chart bump
• Migrate the settings in: https://gitlab.com/gitlab-com/gl-infra/k8s-workloads/gitlab-com/-/blob/master/releases/gitlab/values/values.yaml.gotmpl#L62-63