Bump ember-auto-import from 1.5.3 to 1.6.0

Bumps [ember-auto-import](https://github.com/ef4/ember-auto-import) from 1.5.3 to 1.6.0.
- [Release notes](https://github.com/ef4/ember-auto-import/releases)
- [Changelog](https://github.com/ef4/ember-auto-import/blob/master/CHANGELOG.md)
- [Commits](embroider-build/ember-auto-import@v1.5.3...v1.6.0)

Signed-off-by: dependabot-preview[bot] <[email protected]>

Author: dependabot-preview[bot]