XR settings are shared between platforms

Steps to reproduce:
1. Create a new project
2. Install either OpenXR or OculusXR plugin through the XR Management plugin in Player Settings
3. Make sure you are on Windows/Mac/Linux platform
4. Enable either OpenXR or OculusXR
5. Switch to Windows Dedicated server build
6. Disable XR Plugins and switch back to Windows/Mac/Linux platform
7. Observe that XR plugins are disabled

Expected Result: XR settings should be stored per platform and not shared between all of them
Actual Result: XR settings are shared between platforms

Reproducible with: 2021.3.33f1, 2022.3.17f1, 2023.2.6f1, 2023.3.0b3

Testing Environment: Windows 11
Not reproducible on: No other environment tested