Kerning of text inside math environment is wrong

I noticed a few instances of broken kerning (also present in `main` now):

...is this caused by the font or rather by a surprise math mode?

EDIT: I found the issue is rather typst using math font to typeset the contents of `italics` (or `text(...)`) although the documentation seems to imply otherwise.

I tried with IBM Plex, which gives a really nice render, try:

```typst
#set text( font: "IBM Plex Serif")
#show raw: set text(font: "IBM Plex Mono")
```

EDIT2: it's typst. https://github.com/typst/typst/issues/366

_Originally posted by @exaexa in https://github.com/haskellfoundation/haskell-2010-revised-report/pull/43#pullrequestreview-5202358904_

Start by reproducing the reported rendering in the Haskell report and with the IBM Plex Serif and IBM Plex Mono settings shown in the issue. Compare text inside math, italics, and text(...) with the intended font behavior; done means the affected passages no longer use incorrect math-font kerning, or the issue is documented as dependent on Typst issue 366.

Written by the indexing model from the issue text.