fix: custom items in ItemRequirement

rpgregions/src/main/java/net/islandearth/rpgregions/requirements/ItemRequirement.java

@@ -26,7 +26,13 @@ public class ItemRequirement extends RegionRequirement {
 
     @Override
     public boolean meetsRequirements(Player player) {
-        final boolean hasItem = player.getInventory().containsAtLeast(itemStack, 1);
+        boolean hasItem = false;
+        for (ItemStack content : player.getInventory().getContents()) {
+            if (content.isSimilar(itemStack)) {
+                hasItem = true;
+                break;
+            }
+        }
         return inverse != hasItem;
     }