Bump serialize-javascript and mocha in /scripts/extensions/helloWorld

Bumps [serialize-javascript](https://github.com/yahoo/serialize-javascript) to 6.0.2 and updates ancestor dependency [mocha](https://github.com/mochajs/mocha). These dependencies need to be updated together.


Updates `serialize-javascript` from 5.0.1 to 6.0.2
- [Release notes](https://github.com/yahoo/serialize-javascript/releases)
- [Commits](yahoo/serialize-javascript@v5.0.1...v6.0.2)

Updates `mocha` from 8.4.0 to 11.1.0
- [Release notes](https://github.com/mochajs/mocha/releases)
- [Changelog](https://github.com/mochajs/mocha/blob/main/CHANGELOG.md)
- [Commits](mochajs/mocha@v8.4.0...v11.1.0)

---
updated-dependencies:
- dependency-name: serialize-javascript
  dependency-type: indirect
- dependency-name: mocha
  dependency-type: direct:development
...

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