build(deps-dev): bump @ember/test-helpers from 2.2.8 to 2.2.9 (#133)

Bumps [@ember/test-helpers](https://github.com/emberjs/ember-test-helpers) from 2.2.8 to 2.2.9.
- [Release notes](https://github.com/emberjs/ember-test-helpers/releases)
- [Changelog](https://github.com/emberjs/ember-test-helpers/blob/master/CHANGELOG.md)
- [Commits](emberjs/ember-test-helpers@v2.2.8...v2.2.9)

---
updated-dependencies:
- dependency-name: "@ember/test-helpers"
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

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

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

yarn.lock

@@ -999,9 +999,9 @@
     silent-error "^1.1.1"
 
 "@ember/test-helpers@^2.1.4":
-  version "2.2.8"
-  resolved "https://registry.yarnpkg.com/@ember/test-helpers/-/test-helpers-2.2.8.tgz#3f1c1ab828098e4a6a6209b7c28b124ac614a73f"
-  integrity sha512-1en4cBDoI3+1xtl7k5QtGpPgKmuvF0D7Azs0JSlv3ttV1Fxb3ukLZ/2Giz1IOEMogO4B+k7fGFeYpANVJuNWqA==
+  version "2.2.9"
+  resolved "https://registry.yarnpkg.com/@ember/test-helpers/-/test-helpers-2.2.9.tgz#68cceb50ad5b8adedad5d8bf73b39ff71a07f4a6"
+  integrity sha512-QLwV2ASk7XB9+SLCNKFu+y9iNbTsH2Ah3eaJiHZ01uDgVsYZZfJCINhUB9/sY19VagBQnP5Te3QowI6qw3XeLA==
   dependencies:
     "@ember/test-waiters" "^2.4.4"
     broccoli-debug "^0.6.5"