Consider removing polyfill because MathJax should no longer need it

[yutannihilation]

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:

mathjax/MathJax-src#62

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)

[yutannihilation]

Thanks for fixing!

[jgm]

Thanks for the suggestion. I'd actually forgotten that we even had this.