fix(_official-realtime-app): fix dev script

[MichaelDeBoey]

Closes #106

[machour]

Doesn't seem to work at all for me on v16, v18 or even v19.
Any action seems to instantly revert, and the event is never broadcasted to the other window.

Here's what I'm seeing:

Screen.Recording.2023-01-18.at.3.22.35.PM.mov

If I get back to the main, it works again for me on v19

[MichaelDeBoey]

@machour It was also working before locally, so probably the build cache or so that was out of date when I checked 🤔

Strange that it doesn't work as server.js was the default one without extras, so removing it (and the express adapter) and using just remix dev should work normally 🤔

@sergiodxa Could this be because we're not using the express adapter anymore & remix-utils need it when using useEventSource?

[mcansh]

this PR appears to work again (with Remix 1.12.0)