Bump shelljs and jshint

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


Removes `shelljs`

Updates `jshint` from 2.13.1 to 2.13.6
- [Release notes](https://github.com/jshint/jshint/releases)
- [Changelog](https://github.com/jshint/jshint/blob/main/CHANGELOG.md)
- [Commits](jshint/jshint@2.13.1...2.13.6)

---
updated-dependencies:
- dependency-name: shelljs
  dependency-type: indirect
- dependency-name: jshint
  dependency-type: direct:development
...

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