enhance: remove --ui option

[njhale]

Remove the ability to start the UI tool from gptscript. This drops the --ui flag from the gptscript command.

Note: Let's hold off on merging this until electron support is merged into https://github.com/gptscript-ai/ui.

[njhale]

@thedadams

Should we also remove the workflow that tags the UI? Last I heard, the UI electron app was going to be on a slightly different release cycle

I think that's a good idea since there's currently at least one manual step -- bumping the version field in the package.json file -- to releasing the UI. As it stands, we'll end up inadvertently updating the published builds for the previous release of the UI when gptscript releases.

I'll drop the workflow now.

[njhale]

done

[njhale]

This is stale, going to close out.