Bump ember-cli from 3.9.0 to 6.1.0

Bumps [ember-cli](https://github.com/ember-cli/ember-cli) from 3.9.0 to 6.1.0.
- [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@v3.9.0...v6.1.0)

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

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

package.json

@@ -56,7 +56,7 @@
     "broccoli-test-helper": "^2.0.0",
     "chai": "^4.3.4",
     "chai-fs": "^2.0.0",
-    "ember-cli": "~3.9.0",
+    "ember-cli": "~6.1.0",
     "ember-cli-addon-tests": "^0.11.1",
     "ember-cli-dependency-checker": "^3.2.0",
     "ember-cli-fastboot": "^2.2.3",