fixup! perf(@angular/build): optimize library dts bundling and enable dts tree-shaking

Author: alan-agius4

packages/angular/build/src/builders/library/pipeline/bundler.ts

@@ -31,9 +31,13 @@ let rolldownPluginDtsPromise: Promise<RolldownPluginDtsModule> | undefined;
  * @returns A promise resolving to the `rolldown-plugin-dts` module namespace.
  */
 function loadRolldownPluginDts(): Promise<RolldownPluginDtsModule> {
-  return (rolldownPluginDtsPromise ??= loadRolldown().then(
-    () => import('rolldown-plugin-dts' as string) as Promise<RolldownPluginDtsModule>,
-  ));
+  return (rolldownPluginDtsPromise ??= (async () => {
+    // Ensure Rolldown's native binding is initialized via `loadRolldown()` before evaluating
+    // `rolldown-plugin-dts`, which has top-level imports of `rolldown/experimental`.
+    await loadRolldown();
+
+    return import('rolldown-plugin-dts' as string) as Promise<RolldownPluginDtsModule>;
+  })());
 }
 
 /**