Bump tar and bcrypt in /examples/nextjs (#563)

Removes [tar](https://github.com/isaacs/node-tar). It's no longer used after updating ancestor dependency [bcrypt](https://github.com/kelektiv/node.bcrypt.js). These dependencies need to be updated together.


Removes `tar`

Updates `bcrypt` from 5.1.1 to 6.0.0
- [Release notes](https://github.com/kelektiv/node.bcrypt.js/releases)
- [Changelog](https://github.com/kelektiv/node.bcrypt.js/blob/master/CHANGELOG.md)
- [Commits](kelektiv/node.bcrypt.js@v5.1.1...v6.0.0)

---
updated-dependencies:
- dependency-name: tar
  dependency-version: 
  dependency-type: indirect
- dependency-name: bcrypt
  dependency-version: 6.0.0
  dependency-type: direct:production
...

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Co-authored-by: Stefan Becker <586690+snacker81@users.noreply.github.com>

Author: dependabot[bot]