Bump ws from 6.2.1 to 6.2.2 in /demo

Bumps [ws](https://github.com/websockets/ws) from 6.2.1 to 6.2.2.
- [Release notes](https://github.com/websockets/ws/releases)
- [Commits](https://github.com/websockets/ws/commits)

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

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Author: dependabot[bot]