Remove unused dev dependencies

These dependencies are mostly only needed for addons that publish their dummy app somewhere. We don't do that, so we don't need those dependencies either.

package.json

@@ -35,18 +35,12 @@
     "@glimmer/component": "^1.0.0",
     "@glimmer/tracking": "^1.0.0",
     "babel-eslint": "^10.0.3",
-    "broccoli-asset-rev": "^3.0.0",
-    "ember-ajax": "^3.1.0",
     "ember-cli": "~3.16.0",
     "ember-cli-dependency-checker": "^3.2.0",
     "ember-cli-inject-live-reload": "^2.0.2",
-    "ember-cli-release": "^0.2.9",
-    "ember-cli-sri": "^2.1.1",
     "ember-cli-testdouble": "^0.1.3",
     "ember-cli-testdouble-qunit": "^2.1.1",
-    "ember-cli-uglify": "^3.0.0",
     "ember-disable-prototype-extensions": "^1.1.3",
-    "ember-export-application-global": "^2.0.1",
     "ember-load-initializers": "^2.1.1",
     "ember-maybe-import-regenerator": "^0.1.6",
     "ember-qunit": "^4.6.0",