refactor: make Structure#deleted a getter to a WeakSet (#7074)

src/structures/Sticker.js

@@ -4,6 +4,13 @@ const Base = require('./Base');
 const { StickerFormatTypes, StickerTypes } = require('../util/Constants');
 const SnowflakeUtil = require('../util/SnowflakeUtil');
 
+/**
+ * @type {WeakSet<StageInstance>}
+ * @private
+ * @internal
+ */
+const deletedStickers = new WeakSet();
+
 /**
  * Represents a Sticker.
  * @extends {Base}
@@ -137,6 +144,19 @@ class Sticker extends Base {
     return new Date(this.createdTimestamp);
   }
 
+  /**
+   * Whether or not the stage instance has been deleted
+   * @type {boolean}
+   */
+  get deleted() {
+    return deletedStickers.has(this);
+  }
+
+  set deleted(value) {
+    if (value) deletedStickers.add(this);
+    else deletedStickers.delete(this);
+  }
+
   /**
    * Whether this sticker is partial
    * @type {boolean}
@@ -264,7 +284,8 @@ class Sticker extends Base {
   }
 }
 
-module.exports = Sticker;
+exports.Sticker = Sticker;
+exports.deletedStickers = deletedStickers;
 
 /**
  * @external APISticker