⬆️ Bump ember-cli from 3.28.3 to 3.28.4 (#446)

Bumps [ember-cli](https://github.com/ember-cli/ember-cli) from 3.28.3 to 3.28.4.
- [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@v3.28.3...v3.28.4)

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

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

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

yarn.lock

@@ -4771,9 +4771,9 @@ ember-cli-version-checker@^5.1.1, ember-cli-version-checker@^5.1.2:
     silent-error "^1.1.1"
 
 ember-cli@~3.28.0:
-  version "3.28.3"
-  resolved "https://registry.yarnpkg.com/ember-cli/-/ember-cli-3.28.3.tgz#3384c3fb018b58111e30efed15a2f6a9b66b84c3"
-  integrity sha512-DddAQAddbyaOU4NAjTt8g+FoCCK/F00kbj9pcHO1lfAUpIUS9JPBoWxxZ3qO08mUNXi50pdQSPVVRWzN7mNz2g==
+  version "3.28.4"
+  resolved "https://registry.yarnpkg.com/ember-cli/-/ember-cli-3.28.4.tgz#784cfeaf5319e409edc3e03e5d99bcfcf18f9e53"
+  integrity sha512-bRQpZqx1YctDNR7gb5CXfXYkZtieMh4F6v6bZtu+Da8jWTKoGizG1LXsG/Bhs96USPjlZZsErkSBo6qiGjJlcA==
   dependencies:
     "@babel/core" "^7.13.8"
     "@babel/plugin-transform-modules-amd" "^7.12.1"