Reproduction steps:
1. Install Version Control - Perforce (P4V)
2. Create a new Workspace in Perforce
3. Create a new project in the Workspace's root folder
4. Install UI builder
5. Create .uxml and .uss files in Window -> UI (Toolkit) -> UI Builder
6. Submit changes to the Workspace in P4V, but do not Check out
7. Try to edit and save .uss file in Window -> UI (Toolkit) -> UI Builder

Expected result: Version Control does not conflict with Unity and lets the user edit UI Builder files (.uss, .uxml)
Actual result: This error is thrown: "UnauthorizedAccessException: Access to the path "...uss" is denied.". The user is unable to save the file.

Reproducible with: 0.11.2-preview - 1.0.0-preview.12 (2019.4.23f1, 2020.3.2f1, 2021.1.0f1, 2021.2.0a10)

Notes:
- https://www.perforce.com/downloads/helix-visual-client-p4v
- No such problem when editing anything else in the Scene