chore(deps-dev): bump ember-source from 4.12.4 to 5.12.0

Bumps [ember-source](https://github.com/emberjs/ember.js) from 4.12.4 to 5.12.0.
- [Release notes](https://github.com/emberjs/ember.js/releases)
- [Changelog](https://github.com/emberjs/ember.js/blob/main/CHANGELOG.md)
- [Commits](emberjs/ember.js@v4.12.4...v5.12.0)

---
updated-dependencies:
- dependency-name: ember-source
  dependency-type: direct:development
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

package.json

@@ -105,7 +105,7 @@
     "ember-page-title": "^7.0.0",
     "ember-qunit": "^7.0.0",
     "ember-resolver": "^8.0.3",
-    "ember-source": "~4.12.3",
+    "ember-source": "~5.12.0",
     "ember-source-channel-url": "^3.0.0",
     "ember-style-modifier": "^0.8.0",
     "ember-template-imports": "^4.1.2",