Pusher change history: MT1 cluster - increased latency

Pusher reported major increased latency on Channels cluster `mt1`, affecting Channels Dashboard, Channels presence channels, Channels REST API and Channels WebSocket client API. It started at 2025-10-20 17:26 UTC and was resolved at 2025-10-21 07:14 UTC, lasting 13 h 48 min. Pusher attributed the latency to an external cloud-provider incident.