Rendering quarto presentation to pdf from html leaves (mostly) blank page when `notes` exist

Hi,

I think this may be completely intentional, but I noticed that when there is a speaker note on a slide, the slide gets split into 2 pages when saved to pdf with renderthis::to_pdf().

For example, slide 1 below gets split into pages 2 and 3 in the pdf (after the title slide on page 1), while slide 2 is, as expected, only on page 4.

---
title: "test"
format: revealjs
---

## slide 1

![](https://allisonhorst.github.io/palmerpenguins/reference/figures/README-flipper-bill-1.png)

::: notes
-   secret note
:::

## slide 2

![](https://allisonhorst.github.io/palmerpenguins/reference/figures/README-flipper-bill-1.png)

renderthis::to_pdf("test.html")

I don't think I can insert the html into this PR, but here's the resulting pdf.

Start with the Quarto revealjs example in the issue and run renderthis::to_pdf("test.html") to compare slides with and without a notes block. Done means a slide containing notes no longer produces an extra mostly blank PDF page.