feat: remove custom equals method from Npc class

Author: TheBjoRedCraft

surf-npc-api/src/main/kotlin/dev/slne/surf/npc/api/npc/Npc.kt

@@ -176,6 +176,4 @@ interface Npc {
      * @param animationType The type of animation to play.
      */
     fun playAnimation(animationType: NpcAnimationType)
-
-    override fun equals(other: Any?): Boolean
 }