Package Manager's Package list is immediately scrolled when using keyboard navigation

Steps to reproduce:

1. Create a new project
2. Open Package Manager window (Window -> Package Management -> Package Manager)
3. Switch to the Unity Registry tab
4. Select one of the Packages
5. Use the keyboard's arrow keys to navigate the package list up and down

Actual results: The package list is immediately scrolled when using the arrow keys to navigate the list, which leads to stuttering when the selected item is at the top or bottom of the list's ScrollView

Expected results: The package list is only scrolled when the newly selected package is not in the list's ScrollView

Reproducible with versions: 6000.6.0a7, 6000.6.0b4, 6000.7.0a2

Not reproducible with versions: 6000.0.79f1, 6000.3.20f1, 6000.5.4f1, 6000.6.0a6

Tested on (OS): macOS 26.5.1, Windows 11