Missed that this no longer needs a promise!

packages/perseus/src/init.ts

@@ -7,14 +7,11 @@ import * as Widgets from "./widgets";
  * needed via `loadExtraWidgets`. It is idempotent, so it's not a problem to
  * call it multiple times.
  */
-const init = function (): Promise<undefined> {
+const init = function () {
     Widgets.registerWidgets(basicWidgets);
     Widgets.registerWidgets(extraWidgets);
 
     Widgets.replaceDeprecatedWidgets();
-
-    // @ts-expect-error - TS2322 - Type 'Promise<void>' is not assignable to type 'Promise<undefined>'.
-    return Promise.resolve();
 };
 
 export default init;