Bump @types/ember-feature-flags from 4.0.9 to 6.0.0

Bumps [@types/ember-feature-flags](https://github.com/DefinitelyTyped/DefinitelyTyped/tree/HEAD/types/ember-feature-flags) from 4.0.9 to 6.0.0.
- [Release notes](https://github.com/DefinitelyTyped/DefinitelyTyped/releases)
- [Commits](https://github.com/DefinitelyTyped/DefinitelyTyped/commits/HEAD/types/ember-feature-flags)

---
updated-dependencies:
- dependency-name: "@types/ember-feature-flags"
  dependency-type: direct:development
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

package.json

@@ -70,7 +70,7 @@
     "@types/ember-data__model": "^3.16.2",
     "@types/ember-data__serializer": "^3.16.1",
     "@types/ember-data__store": "^3.16.1",
-    "@types/ember-feature-flags": "^4.0.5",
+    "@types/ember-feature-flags": "^6.0.0",
     "@types/ember-qunit": "^3.4.13",
     "@types/ember-resolver": "^5.0.10",
     "@types/ember__application": "^3.16.2",
@@ -142,7 +142,7 @@
     "ember-cli-showdown": "^4.4.4",
     "ember-cli-sri": "^2.1.1",
     "ember-cli-string-helpers": "^5.0.0",
-    "ember-cli-stylelint": "^2.1.0",
+    "ember-cli-stylelint": "^4.0.0",
     "ember-cli-terser": "^4.0.1",
     "ember-cli-test-loader": "^2.2.0",
     "ember-cli-typescript": "^4.1.0",
@@ -194,7 +194,7 @@
     "ember-radio-button": "^2.0.0",
     "ember-resolver": "^8.0.2",
     "ember-responsive": "^3.0.0",
-    "ember-simple-auth": "^1.6.0",
+    "ember-simple-auth": "^2.1.1",
     "ember-sinon": "^5.0.0",
     "ember-sinon-qunit": "^5.0.0",
     "ember-sortable": "2.2",
@@ -222,7 +222,7 @@
     "jsonapi-typescript": "^0.1.3",
     "katex": "^0.11.1",
     "keen-analysis": "^2.0.0",
-    "keen-dataviz": "^2.0.4",
+    "keen-dataviz": "^3.15.5",
     "keen-tracking": "^2.0.9",
     "lint-staged": "^8.1.5",
     "liquid-fire": "^0.30.0",