Add ember string to the test app

Author: NullVoxPopuli

pnpm-lock.yaml

@@ -27,6 +27,7 @@
   "devDependencies": {
     "@babel/eslint-parser": "^7.21.3",
     "@babel/plugin-proposal-decorators": "^7.21.0",
+    "@ember/jquery": "^2.0.0",
     "@ember/optional-features": "^2.0.0",
     "@ember/string": "^3.0.1",
     "@ember/test-helpers": "workspace:*",