build(deps): bump highlight.js from 9.18.1 to 9.18.5 in /www/website

Bumps [highlight.js](https://github.com/highlightjs/highlight.js) from 9.18.1 to 9.18.5.
- [Release notes](https://github.com/highlightjs/highlight.js/releases)
- [Changelog](https://github.com/highlightjs/highlight.js/blob/9.18.5/CHANGES.md)
- [Commits](highlightjs/highlight.js@9.18.1...9.18.5)

Signed-off-by: dependabot[bot] <[email protected]>