Remove alert deprecation notice from metrics dashboard when the deprecation is complete

In #328774 (closed) we are adding an alert letting users know about the deprecation of alerts. We'll also need to remove this notice after the deprecation is complete.

changed milestone to %14.0

added devopsmonitor grouprespond labels

mentioned in issue #328774 (closed)

mentioned in issue #327796 (closed)

marked this issue as related to #327796 (closed)

added [deprecated] Accepting merge requests label

mentioned in epic &5877

added to epic &5877

added sectionops label

added Deliverable workflowready for development labels

assigned to @tristan.read

removed [deprecated] Accepting merge requests label

added workflowverification label and removed workflowready for development label

Closing, as !63838 (merged) completes this and is deployed to production.

closed

added workflowproduction label and removed workflowverification label