FixItemDespawn in 1.21

FixItemDespawn addresses a significant issue in the latest versions of Minecraft: items at the edge of the simulation distance not despawning as they should. These items accumulate over time, consuming memory and server resources, which can lead to performance problems, especially when plugins that manage entities start to struggle, causing the server to lag.

This plugin introduces a created_at field to item entities, allowing it to track when each item was spawned and automatically remove it after the configured time limit is reached. The existing Paper configuration option (alt-item-despawn-rate) does not resolve this issue, and currently, the Paper development team has no solution for it.

Please note that this plugin is a quick fix for what is hopefully a temporary problem in the current Minecraft version. It will not receive further updates or support.

Important: Upon installing this plugin, all items currently on the ground will despawn immediately.