[ShadowRealm] Remove unused pending_exception

Fix GCC compilation complaints.

Bug: v8:11989
Change-Id: I547e61342be090cc31825d8fe49463a79a39495f
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3553789Reviewed-by: Shu-yu Guo <syg@chromium.org>
Commit-Queue: Shu-yu Guo <syg@chromium.org>
Cr-Commit-Position: refs/heads/main@{#79643}

src/objects/js-function.cc

@@ -457,8 +457,6 @@ MaybeHandle<Object> JSWrappedFunction::Create(
   // 8. If result is an Abrupt Completion, throw a TypeError exception.
   if (is_abrupt.IsNothing()) {
     DCHECK(isolate->has_pending_exception());
-    Handle<Object> pending_exception =
-        Handle<Object>(isolate->pending_exception(), isolate);
     isolate->clear_pending_exception();
     // TODO(v8:11989): provide a non-observable inspection on the
     // pending_exception to the newly created TypeError.