"Invalid StyleProperty" errors are spammed in the Console when the Animation tab is active with a Panel Renderer property added after enabling UI Toolkit Animation

Steps to reproduce:

1. Create a new 3D URP project
2. In the Hierarchy, right-click > UI Toolkit > Standard Elements > Button (or any other element)
3. Save and exit In Context editing
4. Open Animation tab
5. Select the "New UXML" GameObject and click Create (to create Animation Clip)
6. Click "Add Property" then Panel Renderer (UI Toolkit) > Enabled
7. Save and go to Project Settings > UI Toolkit
8. Enable "Enable UI Toolkit Animation" property
9. Close and reopen the Editor (make sure Animation tab is active)
10. Observe the Console

Actual results: Different "Invalid StyleProperty!" errors are spammed as the Animation tab is active

Expected results: No errors are shown

Reproducible with versions: 6000.6.0b4, 6000.7.0a3

Can’t test with versions: 6000.3.20f1, 6000.5.5f1 (no In Context editing)

Tested on (OS): macOS 26.5