Bump ember-source from 4.3.0 to 4.6.0 in /test-app

Bumps [ember-source](https://github.com/emberjs/ember.js) from 4.3.0 to 4.6.0.
- [Release notes](https://github.com/emberjs/ember.js/releases)
- [Changelog](https://github.com/emberjs/ember.js/blob/master/CHANGELOG.md)
- [Commits](emberjs/ember.js@v4.3.0...v4.6.0)

---
updated-dependencies:
- dependency-name: ember-source
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

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

test-app/package.json

@@ -58,7 +58,7 @@
     "ember-qunit": "^5.1.5",
     "ember-resolver": "^8.0.3",
     "ember-set-helper": "^2.0.1",
-    "ember-source": "~4.3.0",
+    "ember-source": "~4.6.0",
     "ember-source-channel-url": "^3.0.0",
     "ember-template-lint": "^4.4.2",
     "ember-test-selectors": "^6.0.0",