Update dependency ember-cli to v4.9.0

Author: renovate[bot]

package.json

@@ -87,7 +87,7 @@
 		"@ember/optional-features": "2.0.0",
 		"babel-eslint": "10.1.0",
 		"broccoli-asset-rev": "3.0.0",
-		"ember-cli": "4.8.0",
+		"ember-cli": "4.9.0",
 		"ember-cli-dependency-checker": "3.3.1",
 		"ember-cli-github-pages": "0.2.2",
 		"ember-cli-head": "2.0.0",