There is a pure rust library for rendering pdfs to png(or bitmap) and svg: https://github.com/LaurenzV/hayro. It is used by typst for pdf image[1]. Although it might not be as mature as mupdf.
I actually chatted for a bit with Laurenz (the developer) and he recommended against using hayro in my case for the time being.
It is however part of (or dependent on) the larger linebender group of crates and will most likely be the best option in the future.