collab: Remove unused `From` impl for `User` model to `proto::User` (#56548)

This PR removes a `From` impl from the database `User` model to
`proto::User`, as it is no longer used.

Release Notes:

- N/A
6e8eaab25bMarshall Bowers committed on 5/12/2026, 4:21:58 PM· committed by GitHubparent011bbf7
1 file changedLine totals unavailable