[explicit-resource-management] Return undefined from dispose builtin

This CL fixes the bug of returning true in dispose method of
DisposableStack.

Bug: 385547086
Change-Id: Iddb72962bd5f7de1ee9346cda3094e98e0565119
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/6119280
Reviewed-by: Shu-yu Guo <syg@chromium.org>
Commit-Queue: Rezvan Mahdavi Hezaveh <rezvan@chromium.org>
Cr-Commit-Position: refs/heads/main@{#97920}

test/staging/explicit-resource-management/async-disposable-stack-dispose-async-resolved-by-undefined.js

@@ -0,0 +1,18 @@
+// Copyright (C) 2024 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+description: |
+  AsyncDisposableStack resolved with undefned.
+includes: [asyncHelpers.js]
+flags: [async]
+features: [explicit-resource-management]
+---*/
+
+asyncTest(async function() {
+    async function TestAsyncDisposableStackDefer() {
+      let stack = new AsyncDisposableStack();
+      assert.sameValue(await stack.disposeAsync(), undefined);
+    };
+    await TestAsyncDisposableStackDefer();
+  });

test/staging/explicit-resource-management/disposable-stack-dispose-return-undefined.js

@@ -0,0 +1,13 @@
+// Copyright (C) 2024 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+description: |
+  DisposableStack return undefned.
+features: [explicit-resource-management]
+---*/
+
+(function TestDisposableStackDisposeReturnsUndefined() {
+    let stack = new DisposableStack();
+    assert.sameValue(stack.dispose(), undefined);
+})();