Update dependency ember-source to v6.9.0

Author: renovate[bot]

package.json

@@ -71,7 +71,7 @@
     "ember-power-select": "8.12.0",
     "ember-qunit": "9.0.4",
     "ember-resolver": "13.1.1",
-    "ember-source": "6.8.2",
+    "ember-source": "6.9.0",
     "ember-source-channel-url": "3.0.0",
     "ember-template-lint": "7.9.3",
     "ember-try": "4.0.0",