Clean unnecessary 'attachToDocument' in 'ee/spec/frontend/dependencies'

Summary

As described in &2419 (closed), we need to clean up our Jest tests from unnecessary attachToDocument usage

Risks

No risks

Involved specs

• ee/spec/frontend/dependencies/components/app_spec.js
• ee/spec/frontend/dependencies/components/dependencies_actions_spec.js
• ee/spec/frontend/dependencies/components/dependency_license_links_spec.js