Update dependency ember-qunit to v9

Author: renovate[bot]

package.json

@@ -53,7 +53,7 @@
     "ember-disable-prototype-extensions": "1.1.3",
     "ember-load-initializers": "2.1.2",
     "ember-maybe-import-regenerator": "1.0.0",
-    "ember-qunit": "6.0.0",
+    "ember-qunit": "9.0.3",
     "ember-resolver": "8.1.0",
     "ember-source": "4.12.0",
     "ember-try": "^3.0.0",