Bump simple-git and generator-jhipster

Bumps [simple-git](https://github.com/steveukx/git-js/tree/HEAD/simple-git) to 3.19.0 and updates ancestor dependency [generator-jhipster](https://github.com/jhipster/generator-jhipster). These dependencies need to be updated together.


Updates `simple-git` from 3.13.0 to 3.19.0
- [Release notes](https://github.com/steveukx/git-js/releases)
- [Changelog](https://github.com/steveukx/git-js/blob/main/simple-git/CHANGELOG.md)
- [Commits](https://github.com/steveukx/git-js/commits/[email protected]/simple-git)

Updates `generator-jhipster` from 7.9.3 to 8.0.0-beta.1
- [Release notes](https://github.com/jhipster/generator-jhipster/releases)
- [Commits](jhipster/generator-jhipster@v7.9.3...v8.0.0-beta.1)

---
updated-dependencies:
- dependency-name: simple-git
  dependency-type: indirect
- dependency-name: generator-jhipster
  dependency-type: direct:development
...

Signed-off-by: dependabot[bot] <[email protected]>