ci: upgrade github actions

[ChristianMurphy]

Initial checklist

• [x] I read the support docs
• [x] I read the contributing guide
• [x] I agree to follow the code of conduct
• [x] I searched issues and couldn’t find anything (or linked relevant results below)
• [x] If applicable, I’ve added docs and tests

Description of changes

setup-node now supports named versions. codecov-action version 1 has been sunset and no longer functions

[remcohaszing]

CI is failing for the same reasons as explained in https://github.com/rehypejs/rehype/pull/119#issuecomment-1318331869.

[wooorm]

Thanks, done in https://github.com/unifiedjs/unified/commit/5f4f1752db3739fa047accda23328a65886ae802!

[github-actions[bot]]

Hi! This was closed. Team: If this was merged, please describe when this is likely to be released. Otherwise, please add one of the no/* labels.