collab: Remove `GET /user` endpoint (#35301)

This PR removes the `GET /user` endpoint, as it has been moved to
`cloud.zed.dev`.

Release Notes:

- N/A
d2d116cb02Marshall Bowers committed on 7/29/2025, 10:34:04 PM· committed by GitHubparent9f69b53
2 files changedLine totals unavailable