matrix-appservice-irc: Planned server restart on Libera causes the bridge to be silently unavailable for 2.5 hours

Libera had a planned netsplit today at 19:55 UTC, and still has not recovered at the time I am writing this. No message is going from IRC to Matrix, and most Matrix users’ messages are not sent to IRC, because their puppets did not reconnect.

Additionally, the org.matrix.appservice-irc.connection event is not set on the Matrix side until someone speaks on the IRC side.