Disable legacy metric infra alerting
Summary
With the migration to Mimir completed, we need to disable the alerting from the legacy Prometheus + Thanos instances.
Before we look to completely decommission the old infra we can remove the alertmanager configs to disable the sending of alerts.
This includes prometheus instances in GCE and GKE that are no longer required in Mimir.
We can achieve this by removing the alertmanager section from the prometheus configuration.
Edited by Nick Duff