Update dependency @ember/test-helpers to v2.9.1 (#1048)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

package.json

@@ -55,7 +55,7 @@
   },
   "devDependencies": {
     "@ember/optional-features": "2.0.0",
-    "@ember/test-helpers": "2.9.0",
+    "@ember/test-helpers": "2.9.1",
     "@embroider/test-setup": "1.8.3",
     "auto-dist-tag": "2.1.1",
     "babel-eslint": "10.1.0",

yarn.lock

@@ -1211,10 +1211,10 @@
   dependencies:
     ember-cli-babel "^7.26.6"
 
-"@ember/[email protected].0":
-  version "2.9.0"
-  resolved "https://registry.yarnpkg.com/@ember/test-helpers/-/test-helpers-2.9.0.tgz#8741afe72443a01f2d487292b88cd58e7917a012"
-  integrity sha512-poMnZk12dOt+yGtUvhW7IqUdb1iE2LqOyfsx+8BG3alxOU86A1m21SFiZV5fTwJ1ENCw2GvxpJGyidIItrKf3Q==
+"@ember/[email protected].1":
+  version "2.9.1"
+  resolved "https://registry.yarnpkg.com/@ember/test-helpers/-/test-helpers-2.9.1.tgz#142a8d5175fc79bb328b7af0cd36755c10181050"
+  integrity sha512-1ZFZCnNfkXcQOf6Vxep/vbZMwFLfD+8heiLiQ6LSB5SY9F3VCF1yNslfgtDqmyQZXhAbbhRTDhy+rHuzzpd+yA==
   dependencies:
     "@ember/test-waiters" "^3.0.0"
     "@embroider/macros" "^1.10.0"