collab: Remove `GET /users/look_up` endpoint (#36279)
This PR removes the `GET /users/look_up` endpoint from Collab, as it has
been moved to Cloud.
Release Notes:
- N/A
b9c110e63eMarshall Bowers committed on 8/15/2025, 10:01:41 PM· committed by GitHubparentf642f76