Update dependency @ember/test-helpers to v5

Author: renovate[bot]

package.json

@@ -35,7 +35,7 @@
     "@babel/eslint-parser": "7.26.8",
     "@ember/optional-features": "2.2.0",
     "@ember/string": "3.1.1",
-    "@ember/test-helpers": "3.3.1",
+    "@ember/test-helpers": "5.2.0",
     "@embroider/test-setup": "3.0.3",
     "@glimmer/component": "1.1.2",
     "@glimmer/tracking": "1.1.2",