fixed duplicated display villagers when entities were not loaded yet

arena/src/main/java/eu/mhsl/craftattack/spawn/arena/appliances/arena/Arena.java

@@ -20,6 +20,7 @@ import org.bukkit.Material;
 import org.bukkit.Sound;
 import org.bukkit.World;
 import org.bukkit.attribute.Attribute;
+import org.bukkit.entity.Entity;
 import org.bukkit.entity.Player;
 import org.bukkit.entity.Villager;
 import org.bukkit.event.Listener;
@@ -104,6 +105,7 @@ public class Arena extends Appliance {
         else Main.logger().warning("Arena: pads are not set up, fights cannot be started");
 
         this.syncRegions().forEach(region -> this.worlds.keepLoaded(region, Main.instance()));
+        this.removeStrayVillagers();
         this.placeStarterPlatform();
         this.syncAll();
 
@@ -178,6 +180,25 @@ public class Arena extends Appliance {
             .forEach(this::toTribune);
     }
 
+    /**
+     * Removes old copies of the return villager, for example after its position was changed in the config by hand.
+     */
+    private void removeStrayVillagers() {
+        Region region = this.settings.syncRegion();
+        if(region == null || this.villager == null) return;
+        UUID current = this.villager.getUniqueId();
+        for(int cx = region.minChunkX(); cx <= region.maxChunkX(); cx++) {
+            for(int cz = region.minChunkZ(); cz <= region.maxChunkZ(); cz++) {
+                for(Entity entity : this.worlds.play().getChunkAt(cx, cz).getEntities()) {
+                    if(!(entity instanceof Villager) || entity.getUniqueId().equals(current)) continue;
+                    if(!entity.getScoreboardTags().contains(Displays.MANAGED_TAG)) continue;
+                    entity.remove();
+                    Main.logger().info("Arena: removed a stray return villager at " + entity.getLocation().toVector());
+                }
+            }
+        }
+    }
+
     /**
      * A fresh, empty world gets a small platform at the tribune spawn, so the first visitors do not fall into the void.
      */