renderthis::to_pdf() throw error for HTML slides using mathjax

Hello.

Thanks a lot for this package which I've been using happily for several years.

For some months now, I've been having an issue with some (but not all) symbols in LaTeX equations.

Initially, it seemed to be a quarto issue.

For instance, the following:

## The normal distribution

### Notation

$${\mathcal{N}}(\mu ,\sigma^{2})$$

was producing

Which led me to the fix here

format: 
  revealjs:
    html-math-method: mathjax

But now, that the LaTeX equation displays correctly in the HTML presentation, renderthis::to_pdf() throw the following error and fails to produce the PDF.

> renderthis::to_pdf("index.cluster.html")
Warning: A runtime exception has occured while executing JavaScript
  Runtime exception message:
    TypeError: Cannot read properties of undefined (reading 'Config')
    at http://127.0.0.1:5310/index.cluster_files/libs/revealjs/plugin/math/math.js:1:28635
    at HTMLScriptElement.i (http://127.0.0.1:5310/index.cluster_files/libs/revealjs/plugin/math/math.js:1:28502)

Note that weirdly enough, if I click the 'Print' button in the RStudio 'Presentation' tab, and manually (not programmatically) print it from there, the PDF contains the equation formatted properly.

Any suggestion?

Start by reproducing the failure with renderthis::to_pdf("index.cluster.html") using the MathJax setting shown in the issue, then inspect the generated revealjs/plugin/math/math.js runtime error. Compare this path with the RStudio Presentation tab's manual PDF output. Done means to_pdf produces a PDF with the LaTeX equation rendered correctly.