Test ember-truth-helpers 4.x with older ember-source version

Author: mkszepp

test-app/config/ember-try.js

@@ -18,6 +18,7 @@ module.exports = async function () {
             'ember-qunit': '^6.0.0',
             'ember-resolver': '^8.0.0',
             'ember-source': '~3.28.0',
+            'ember-truth-helpers': '^4.0.3',
           },
         },
       },
@@ -31,6 +32,7 @@ module.exports = async function () {
             'ember-load-initializers': '^2.1.2',
             'ember-resolver': '^8.0.0',
             'ember-source': '~4.4.0',
+            'ember-truth-helpers': '^4.0.3',
           },
         },
       },