build(deps-dev): bump @ember/optional-features from 1.1.0 to 1.2.0
build(deps-dev): bump @ember/optional-features from 1.1.0 to 1.2.0

Bumps [@ember/optional-features](https://github.com/emberjs/ember-optional-features) from 1.1.0 to 1.2.0.
- [Release notes](https://github.com/emberjs/ember-optional-features/releases)
- [Changelog](https://github.com/emberjs/ember-optional-features/blob/master/CHANGELOG.md)
- [Commits](https://github.com/emberjs/ember-optional-features/compare/v1.1.0...v1.2.0)

Signed-off-by: dependabot-preview[bot] <5bdcd3c0d4d24ae3e71b3b452a024c6324c7e4bb@dependabot.com>
samselikoff/ember-cli-mirage,unchartedcode/ember-cli-mirage,samselikoff/ember-cli-mirage,unchartedcode/ember-cli-mirage,samselikoff/ember-cli-mirage,samselikoff/ember-cli-mirage,unchartedcode/ember-cli-mirage,unchartedcode/ember-cli-mirage