fix: problem with multibyte characters in julia engine

[MHellmund]

Description

This concerns the new julia engine and solves issue PumasAI/QuartoNotebookRunner.jl#130

Checklist

I have (if applicable):

• filed a contributor agreement.
• referenced the GitHub issue this PR closes
• updated the appropriate changelog

[cscheid]

I'd like to ensure consistent formatting, but the content looks good. Thank you!

[cscheid]

@MHellmund We also need a contributor agreement from you.

[cscheid]

This looks good! I'll await confirmation on the contributor agreement and we'll merge. Thank you for the good fix!

[MHellmund]

I just sent the contributor agreement to jj@rstudio.com

[MHellmund]

Please don't merge yet, I think I found a problem.

[cscheid]

Got it. Thanks for following up, and good thing I was out on vacation most of last week! :)

[MHellmund]

It's amazing how many tests a wrong code can pass before you run into heisenbugs with a larger document.
I think I've got it now.

[cscheid]

Thanks, @MHellmund! If you have tests you can share publicly, we'd love to run them in our suite going forward.

[MHellmund]

There is the test enclosed to the original bug report PumasAI/QuartoNotebookRunner.jl#130 .
This Quarto book is produced with the new engine. Source. But I don't have a more formal test.