将 Rc<Promise> 的使用转换为 RootedPromise 或 TracedPromise

As discovered in #45262, we leak memory due to how we store `Rc<Promise>` objects that cannot be GCed inside of our DOM objects that are traced by the GC. #47682 and #47735 give us the tools to fix this problem, and we're going to do it in bite-size pieces.