Bump ws and mocha-headless-chrome

Bumps [ws](https://github.com/websockets/ws) to 8.18.3 and updates ancestor dependency [mocha-headless-chrome](https://github.com/direct-adv-interfaces/mocha-headless-chrome). These dependencies need to be updated together.


Updates `ws` from 8.5.0 to 8.18.3
- [Release notes](https://github.com/websockets/ws/releases)
- [Commits](websockets/ws@8.5.0...8.18.3)

Updates `mocha-headless-chrome` from 4.0.0 to 5.1.0
- [Release notes](https://github.com/direct-adv-interfaces/mocha-headless-chrome/releases)
- [Changelog](https://github.com/direct-adv-interfaces/mocha-headless-chrome/blob/master/CHANGELOG.md)
- [Commits](https://github.com/direct-adv-interfaces/mocha-headless-chrome/commits)

---
updated-dependencies:
- dependency-name: ws
  dependency-version: 8.18.3
  dependency-type: indirect
- dependency-name: mocha-headless-chrome
  dependency-version: 5.1.0
  dependency-type: direct:development
...

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

Author: dependabot[bot]