Update dependency @embroider/test-setup to v4

Author: renovate[bot]

package.json

@@ -53,7 +53,7 @@
     "@ember/optional-features": "^2.0.0",
     "@ember/string": "^3.1.1",
     "@ember/test-helpers": "^3.2.0",
-    "@embroider/test-setup": "^3.0.2",
+    "@embroider/test-setup": "^4.0.0",
     "@glimmer/component": "^1.1.2",
     "@glimmer/tracking": "^1.1.2",
     "bootstrap": "^3.3.7",