How to reproduce:
1. Create a new Unity Built-in RP project 
2. If needed, upgrade the project to a reproducible version
3. Go to Window -> Package Management -> Package Manager -> Unity Registry -> Universal Render Pipeline -> Install
4. Go to Window -> Rendering -> Render Pipeline Converter
5. Check the "Rendering Settings" and click "Scan" ("Initialize Converters" in older streams)
6. With the "Rendering Settings" checked, click "Convert Assets" and observe the Console

Expected results: No warnings are thrown
Actual results: "FocusController has unprocessed focus events" warnings are thrown

Reproducible with: 6000.4.0a2, 6000.4.0b9, 6000.5.0a7
Not reproducible with: 6000.0.67f1, 6000.3.9f1, 6000.4.0a1

Reproducible on: Ubuntu 24
Not reproducible on: macOS Tahoe 26 (M1)

Full warning:
FocusController has unprocessed focus events. Clearing.
UnityEngine.GUIUtility:ProcessEvent (int,intptr,bool&) (at /home/bokken/build/output/unity/unity/Modules/IMGUI/GUIUtility.cs:224)

Note: The bug is inconsistent