Fix dom not change while data change

[miyagipipi]

As https://github.com/tnfe/vue3-infinite-list/issues description.
I fix setTimeout to directly run scrollRender().

There may be some doubts about whether the renderEnd function can be removed from the scrollRender function and run separately (involving many changes).

I see that other watch run scrollRender directly. So I haven't made too many modifications here either.

If there is indeed an impact (it operates on DOM), the renderEnd function can be removed from the scrollRender function.
And run renderEnd in watch or some other places.