Build(deps): Bump ember-qunit in /app/assets/javascripts

Bumps [ember-qunit](https://github.com/emberjs/ember-qunit) from 5.1.5 to 6.0.0.
- [Release notes](https://github.com/emberjs/ember-qunit/releases)
- [Changelog](https://github.com/emberjs/ember-qunit/blob/master/CHANGELOG.md)
- [Commits](emberjs/ember-qunit@v5.1.5...v6.0.0)

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

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

app/assets/javascripts/discourse/package.json

@@ -64,7 +64,7 @@
     "ember-load-initializers": "^2.1.1",
     "ember-modifier": "^3.2.7",
     "ember-on-resize-modifier": "^1.1.0",
-    "ember-qunit": "^5.1.5",
+    "ember-qunit": "^6.0.0",
     "ember-rfc176-data": "^0.3.17",
     "ember-source": "~3.28.8",
     "ember-test-selectors": "^6.0.0",