Update dependency @ember/test-helpers to ^5.4.0 (#227)

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

Author: renovate[bot]

package.json

@@ -91,7 +91,7 @@
     "@babel/runtime": "^7.28.4",
     "@ember/app-tsconfig": "^1.0.3",
     "@ember/library-tsconfig": "^1.1.3",
-    "@ember/test-helpers": "^5.3.0",
+    "@ember/test-helpers": "^5.4.0",
     "@embroider/addon-dev": "^8.1.0",
     "@embroider/compat": "^4.1.8",
     "@embroider/core": "^4.2.5",