Localize milestone related time strings (#24051)

- With #23988 in place, we can improve these timestamps

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Co-authored-by: silverwind <me@silverwind.io>

options/locale/locale_en-US.ini

@@ -1710,7 +1710,7 @@ pulls.delete.text = Do you really want to delete this pull request? (This will p
 
 milestones.new = New Milestone
 milestones.closed = Closed %s
-milestones.update_ago = Updated %s ago
+milestones.updated = Updated
 milestones.no_due_date = No due date
 milestones.open = Open
 milestones.close = Close