chore(deps-dev): bump ember-qunit from 3.5.3 to 4.6.0

Bumps [ember-qunit](https://github.com/emberjs/ember-qunit) from 3.5.3 to 4.6.0.
- [Release notes](https://github.com/emberjs/ember-qunit/releases)
- [Changelog](https://github.com/emberjs/ember-qunit/blob/v4.6.0/CHANGELOG.md)
- [Commits](emberjs/ember-qunit@v3.5.3...v4.6.0)

---
updated-dependencies:
- dependency-name: ember-qunit
  dependency-type: direct:development
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>