Fix EntityTargetLivingEntityEvent spam in TemptGoal

[xSnowyk]

Currently, TemptGoal#canUse fires EntityTargetLivingEntityEvent unconditionally every time a valid target is found. Since canContinueToUse delegates to canUse to verify if the player is still valid/holding the item, this results in the event being fired every single tick for every mob being tempted. This creates significant unnecessary overhead and spams plugins that listen to target changes.

This patch adds a check to ensure EntityTargetLivingEntityEvent is only fired when the target actually changes (or is initially found), rather than on every tick of the goal execution.

[electronicboy]

it continuing to fire is somewhat of an expected thing, think a player navigating around a protected region, they shouldn't remain immune; having a timer between attempts (for the same player) might be the better idea here

[xSnowyk]

Checking event plugins 20 times per second for a passive mob walking toward food is an unjustified waste of resources. In my view, a maximum latency of 0.5 seconds for edge cases (like region protection) is a negligible gameplay compromise compared to the performance stability gained by reducing this event spam by 90%