Description
Explain the problem.
polyfill was introduced into Pandoc's template in #8625 because MathJax's document indicated it needs polyfill at the moment. But, now the document doesn't refer to polyfill at all. So, I think Pandoc can just remove the link. As you know, polyfill is to support antique web browsers, so the vast majority users should not be affected.
https://www.mathjax.org/#gettingstarted
After investigating a bit, I found that the reason MathJax started to suggest polyfill was to support IE11, which is end of life on June 14, 2022. This is the original issue:
I'm not sure what browser the reporter of #8625 actually used, but, if it was IE11, I don't think it's a sane idea to keep supporting IE11 in 2023. Needless to say in 2024.
Pandoc version?
Pandoc 3.1.1 (bundled in RStudio IDE)