fix: regression in allowedMentions when replying

backport #10866

src/structures/MessagePayload.js

@@ -257,7 +257,9 @@ class MessagePayload {
       username,
       avatar_url: avatarURL,
       allowed_mentions:
-        this.isMessage && this.target?.author?.id !== this.target?.client?.user?.id ? undefined : allowedMentions,
+        this.isMessage && message_reference === undefined && this.target?.author?.id !== this.target?.client?.user?.id
+          ? undefined
+          : allowedMentions,
       flags,
       message_reference,
       attachments: this.options.attachments,