Update dependency ember-source to v6

Author: renovate[bot]

package.json

@@ -53,7 +53,7 @@
     "ember-page-title": "8.2.4",
     "ember-qunit": "8.1.1",
     "ember-resolver": "11.0.1",
-    "ember-source": "5.12.0",
+    "ember-source": "6.4.0",
     "ember-source-channel-url": "3.0.0",
     "ember-template-lint": "7.0.0",
     "ember-try": "3.0.0",