The Zed provider is now disabled in the selection dropdown when the
current organization has disabled edit predictions. It is also
unselected when you switch organizations to one such organization.

This is also already enforced server side.

Self-Review Checklist:

- [x] I've reviewed my own diff for quality, security, and reliability
- [x] Unsafe blocks (if any) have justifying comments
- [x] The content is consistent with the [UI/UX
checklist](https://github.com/zed-industries/zed/blob/main/CONTRIBUTING.md#uiux-checklist)
- [x] Tests cover the new/changed behavior
- [x] Performance impact has been considered and is acceptable

Release Notes:

- N/A

Co-authored-by: Marshall Bowers <git@maxdeviant.com>