NullPointerException in KnightCombatAI when target is null (MineColonies compatibility)

[yunfang1718128]

When using Better Mob Combat 1.3.0 with MineColonies 1.20.1-1.1.985-snapshot, a NullPointerException occurs when a knight NPC attempts to attack with a null target. The crash happens in the KnightCombatAI.getAttackDamage method when accessing this.target.m_6336()_.
Reproduction Steps

1. Install Minecraft 1.20.1 with Forge 47.4.4
2. Add Better Mob Combat 1.3.0 and MineColonies 1.20.1-1.1.985-snapshot
   3.Create a colony with 2 knight NPCs
   4.Put one mob and then trigger knights' combat behavior
   5.Observe crash when knight tries to attack with another having killed the mob.

Environment Information

Minecraft Version: 1.20.1
Forge Version: 47.4.4
Better Mob Combat Version: 1.3.0
MineColonies Version: 1.20.1-1.1.985-snapshot
Java Version: 17.0.1

Crash Log Snippet
java.lang.NullPointerException:`` Cannot invoke "net.minecraft.world.entity.LivingEntity.m_6336_()" because "this.target" is null at com.minecolonies.core.entity.ai.workers.guard.KnightCombatAI.getAttackDamage(KnightCombatAI.java:269) at com.minecolonies.core.entity.ai.workers.guard.KnightCombatAI.doAttack(KnightCombatAI.java:160) at me.Thelnfamous1.bettermobcombat.logic.MobCombatHelper.lambda$processAttack$0(MobCombatHelper.java:169) at net.minecraft.util.thread.BlockableEventLoop.execute(BlockableEventLoop.java:102)`