Bump tar and js-beautify in /demo/vue_demo/textfsm_online

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


Removes `tar`

Updates `js-beautify` from 1.14.1 to 1.15.4
- [Release notes](https://github.com/beautifier/js-beautify/releases)
- [Changelog](https://github.com/beautifier/js-beautify/blob/main/CHANGELOG.md)
- [Commits](beautifier/js-beautify@v1.14.1...v1.15.4)

---
updated-dependencies:
- dependency-name: tar
  dependency-version: 
  dependency-type: indirect
- dependency-name: js-beautify
  dependency-version: 1.15.4
  dependency-type: direct:production
...

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Author: dependabot[bot]