🐛 Use Item#maxStack for stack size validation in Item#amount

Author: MarcusSlover

src/main/java/com/marcusslover/plus/lib/item/Item.java

@@ -282,7 +282,7 @@ public int maxStack() { // 1.21.3 custom stack size
      * @return the item
      */
     public @NotNull Item amount(int amount) {
-        this.itemStack.setAmount(Math.min(64, Math.max(0, amount)));
+        this.itemStack.setAmount(Math.min(maxStack(), Math.max(0, amount)));
         return this;
     }