This Helm chart is deprecated

Given the incubator repo deprecation timeline (https://github.com/helm/charts#deprecation-timeline), future CockroachDB Helm charts are now located at cockroachdb/charts (https://github.com/cockroachdb/helm-charts/).

The CockroachDB charts repository is already included in the Hubs. Updated installation instructions are included in the new source code repository README (https://github.com/cockroachdb/helm-charts/blob/master/README.md).

Note: incubator/cockroachdb was moved from incubator to stable before a deprecated version was published to this helm repo. Therefore, in order to remove the old versions from aggregators such as Helm Hub (https://hub.helm.sh) and Artifact Hub (https://artifacthub.io/) we have re-added this placeholder deprecated chart. See https://github.com/helm/charts/issues/23128 for further details.
