Bump ember-cli from 3.28.6 to 5.6.0

Bumps [ember-cli](https://github.com/ember-cli/ember-cli) from 3.28.6 to 5.6.0.
- [Release notes](https://github.com/ember-cli/ember-cli/releases)
- [Changelog](https://github.com/ember-cli/ember-cli/blob/master/CHANGELOG.md)
- [Commits](ember-cli/ember-cli@v3.28.6...v5.6.0)

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

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

package.json

@@ -59,7 +59,7 @@
     "@rollup/plugin-babel": "^5.3.0",
     "babel-eslint": "^10.1.0",
     "ember-auto-import": "^2.3.0",
-    "ember-cli": "~3.28.6",
+    "ember-cli": "~5.6.0",
     "ember-cli-babel": "^7.26.10",
     "ember-cli-beta": "npm:ember-cli@beta",
     "ember-cli-htmlbars": "^5.7.2",