Bump qs from 6.6.0 to 6.9.7 in /slides

Bumps [qs](https://github.com/ljharb/qs) from 6.6.0 to 6.9.7.
- [Changelog](https://github.com/ljharb/qs/blob/main/CHANGELOG.md)
- [Commits](ljharb/qs@v6.6.0...v6.9.7)

---
updated-dependencies:
- dependency-name: qs
  dependency-type: indirect
...

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

Author: dependabot[bot]