Bump highlight.js from 9.18.5 to 10.4.1 in /site-ui

Bumps [highlight.js](https://github.com/highlightjs/highlight.js) from 9.18.5 to 10.4.1.
- [Release notes](https://github.com/highlightjs/highlight.js/releases)
- [Changelog](https://github.com/highlightjs/highlight.js/blob/main/CHANGES.md)
- [Commits](highlightjs/highlight.js@9.18.5...10.4.1)

---
updated-dependencies:
- dependency-name: highlight.js
  dependency-version: 10.4.1
  dependency-type: direct:development
...

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Author: dependabot[bot]