Bump widget example to v9

[chrisgervang]

For #7946

Background

Upgrading basic widget example to deck v9. Issue Observed: Beta 2 doesn't publish the stylesheet.css and didn't bundle preact correctly, so yarn start doesn't work. yarn start-local works though, which leads me to believe the preact bundle was fixed with #8460.

The stylesheet still isn't in the dist after running yarn build.. needs investigation.

luma.registerDevices([WebGLDevice]) doesn't seem necessary anymore. Is that right, @felixpalmer @ibgreen?

Change List

• Bump widget example to v9
• Remove luma.registerDevices([WebGLDevice]);