When a combat robot expires and is targeting an artillery wagon, it will now explode. This is a work around for a factorio bug where combat robots do not attack artillery wagons.
Players were using remotely located artillery wagons in lakes to cheesily clear the map with no repercussions. Swarms of destroyer capsules would hover over the artillery but not target it. They would timeout and the player could then refill the wagon with ammo.
I've changed the entity_died_events file to events.lua since it now has on_entity_died, on_player_died and on_combat_robot_expired.
I have added the on_combat_robot_expired event so that when the robots timeout they explode, damaging nearby entities.