build(deps): bump nanoid and mocha in /docker/async-slowapp

Removes [nanoid](https://github.com/ai/nanoid). It's no longer used after updating ancestor dependency [mocha](https://github.com/mochajs/mocha). These dependencies need to be updated together.


Removes `nanoid`

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: nanoid
  dependency-version: 
  dependency-type: indirect
- dependency-name: mocha
  dependency-version: 11.1.0
  dependency-type: direct:development
...

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Author: dependabot[bot]