collab: Remove `PUT /billing/preferences` endpoint (#34825)

This PR removes the `PUT /billing/preferences` endpoint, as it has been
moved to `cloud.zed.dev`.

Release Notes:

- N/A
97af7e1bd9Marshall Bowers committed on 7/21/2025, 3:29:16 PM· committed by GitHubparentc251f2a
1 file changedLine totals unavailable