Description

With the implementation of the new TSDB shipper some metrics previously present in the BoltDB implementation went away, namely the request duration metrics that are used in dashboards. The goal would be to introduce these to TSDB implementation.

With the implementation of the new TSDB shipper, new metrics were introduced to generalize the observability of shippers, those metrics are "loki_index_request_duration_seconds" introduced in https://github.com/grafana/loki/pull/6880. With them new dashboards were also built https://github.com/grafana/loki/pull/7163. We should then remove the old dashboards from the operator

Acceptance Criteria

1. Loki now reports request duration metrics i.e loki_tsdb_shipper_request_duration_seconds
2. Remove the BoltDB Shipper dashboards from the collection of dashboards deployed by the operator

Developer Notes