feat: add new activity flags (#6699)

src/util/ActivityFlags.js

@@ -23,6 +23,9 @@ class ActivityFlags extends BitField {}
  * * `JOIN_REQUEST`
  * * `SYNC`
  * * `PLAY`
+ * * `PARTY_PRIVACY_FRIENDS`
+ * * `PARTY_PRIVACY_VOICE_CHANNEL`
+ * * `EMBEDDED`
  * @type {Object}
  * @see {@link https://discord.com/developers/docs/topics/gateway#activity-object-activity-flags}
  */
@@ -33,6 +36,9 @@ ActivityFlags.FLAGS = {
   JOIN_REQUEST: 1 << 3,
   SYNC: 1 << 4,
   PLAY: 1 << 5,
+  PARTY_PRIVACY_FRIENDS: 1 << 6,
+  PARTY_PRIVACY_VOICE_CHANNEL: 1 << 7,
+  EMBEDDED: 1 << 8,
 };
 
 module.exports = ActivityFlags;