Closes #52115

## Context

Removes the third party edit prediction integration for Sweep AI ahead
of their servers shutting down.

This PR will not affect those who are already use or plan to use their
open weighted models. The code removed by this PR was required for
integrating with their proprietary API.


## Self-Review Checklist

<!-- Check before requesting review: -->
- [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:

- Removed support for using the Sweep AI edit prediction provider
through their proprietary API, as the servers are shutting down
https://discord.com/channels/1100625416022138902/1100625417272045639/1480644297903575142,
https://x.com/wwzeng1/status/2033302698360180949