CI: Enable Ember v4 scenarios again (#740)

Author: Turbo87

.github/workflows/ci.yml

@@ -49,10 +49,9 @@ jobs:
           - embroider-optimized-with-mocha
           - ember-lts-3.24
           - ember-lts-3.20
-          # temporarily disabled until we've fixed support for Ember.js v4
-          # - ember-release
-          # - ember-beta
-          # - ember-canary
+          - ember-release
+          - ember-beta
+          - ember-canary
           - ember-qunit-4
 
     steps: