collab: Remove `POST /billing/subscriptions/manage` endpoint (#34986)
This PR removes the `POST /billing/subscriptions/manage` endpoint, as it
has been moved to `cloud.zed.dev`.
Release Notes:
- N/A
3d4266bb8fMarshall Bowers committed on 7/23/2025, 11:30:00 PM· committed by GitHubparent4a87397