Update TypeScript and add it to test matrix

[charpeni]

Bumping TypeScript from 5.7.3 to 5.8.3 and adding 5.8 to the test matrix.

[pkg-pr-new]

Open in StackBlitz

npm i https://pkg.pr.new/mmkal/expect-type@151

commit: d90bd5c

[mmkal]

Thanks @charpeni! Was this motivated by something in particular - had you seen any issues with typescript 5.8?

[charpeni]

Absolutely not!

Was updating our app from v0 to v1, I looked at the repo and noticed the gap. Wanted to contribute back. Thank you for your great work, I'm a great admirer of this library. See: https://charpeni.com/blog/testing-typescript-types-part-2.