The version bump from 1.13.6 to 1.13.9 suggests these are mostly internal improvements and bug fixes rather than major feature additions.

components/markdown/ButtonMdx.tsx

@@ -1,8 +1,6 @@
 import React from "react";
 import * as Icons from "lucide-react";
 import Link from "next/link";
-
-type IconName = keyof typeof Icons;
 type ButtonProps = {
   icon?: keyof typeof Icons;
   text?: string;