chore: 🤖 upgrade ember dependencies in anticipation of ember 4 (#1280)

* refactor: 💡 replace ember notify with flash in notify decorator

* refactor: 💡 remove embery-notify and replace last instance

* chore: 🤖 upgrade ember dependencies in anticipation of ember 4

addons/api/package.json

@@ -28,7 +28,7 @@
     "ember-auto-import": "^2.4.2",
     "ember-can": "^3.1.0",
     "ember-cli-babel": "^7.26.8",
-    "ember-cli-htmlbars": "^5.7.1",
+    "ember-cli-htmlbars": "^6.1.0",
     "ember-cli-mirage": "^2.2.0",
     "ember-data": "^3.20.0",
     "ember-data-model-fragments": "5.0.0-beta.2",