feat: upgrade to remark 13

[vladar]

Description

Upgraded remark-related packages. Listed all known dom tree changes in the discussion: #30385

BREAKING CHANGES:

• v11 (+remark-stringify@7.0.0, remark-parse@7.0.0, unified@8.0.0)
• v12 (+remark-stringify@8.0.0, remark-parse@8.0.0, unified@9.0.0)
• v13

Plugin deps updated:

• ✅ gatsby-transformer-remark
• ✅ gatsby-remark-autolink-headers
• ✅ gatsby-remark-code-repls
• ✅ gatsby-remark-copy-linked-files
• ⛔ gatsby-remark-custom-blocks (blocked by remark@next (13) zestedesavoir/zmarkdown#416)
• ✅ gatsby-remark-embed-snippet
• ✅ gatsby-remark-graphviz
• ✅ gatsby-remark-images
• ✅ gatsby-remark-images-contentful
• ✅ gatsby-remark-katex
• ✅ gatsby-remark-prismjs
• ✅ gatsby-remark-responsive-iframe
• ✅ gatsby-remark-smartypants

List of remark plugins compatible with v13:
https://github.com/remarkjs/remark/blob/main/doc/plugins.md#list-of-plugins

Discussion

See umbrella discussion #30385

[vladar]

This is a pre-13.0 change (happens even with 12.0) Makes sense to me because now top-level list items have consistent markup (expand above to compare with the item having a sub-list)