fix: drain tasks before shutting down isolate (#17877)

atom/browser/javascript_environment.cc

@@ -74,6 +74,7 @@ void JavascriptEnvironment::OnMessageLoopCreated() {
 void JavascriptEnvironment::OnMessageLoopDestroying() {
   DCHECK(microtasks_runner_);
   base::MessageLoopCurrent::Get()->RemoveTaskObserver(microtasks_runner_.get());
+  platform_->DrainTasks(isolate_);
   platform_->UnregisterIsolate(isolate_);
 }