Bump serve-static and reveal-md in /presentations

Bumps [serve-static](https://github.com/expressjs/serve-static) to 1.16.2 and updates ancestor dependency [reveal-md](https://github.com/webpro/reveal-md). These dependencies need to be updated together.


Updates `serve-static` from 1.15.0 to 1.16.2
- [Release notes](https://github.com/expressjs/serve-static/releases)
- [Changelog](https://github.com/expressjs/serve-static/blob/v1.16.2/HISTORY.md)
- [Commits](expressjs/serve-static@v1.15.0...v1.16.2)

Updates `reveal-md` from 6.1.3 to 6.1.4
- [Release notes](https://github.com/webpro/reveal-md/releases)
- [Changelog](https://github.com/webpro/reveal-md/blob/main/.release-it.json)
- [Commits](webpro/reveal-md@6.1.3...6.1.4)

---
updated-dependencies:
- dependency-name: serve-static
  dependency-type: indirect
- dependency-name: reveal-md
  dependency-type: direct:production
...

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