Update to ember-cli v6.1

This release uses the `babel-remove-types` package that includes the fixes for .gts detyping to work.

Author: Windvis

package.json

@@ -128,7 +128,7 @@
     "babel-plugin-ember-template-compilation": "^2.1.1",
     "dag-map": "^2.0.2",
     "decorator-transforms": "2.0.0",
-    "ember-cli": "^5.12.0",
+    "ember-cli": "^6.1.0",
     "ember-cli-blueprint-test-helpers": "^0.19.2",
     "ember-cli-browserstack": "^2.0.1",
     "ember-cli-dependency-checker": "^3.3.1",