Vertical scrollbar briefly appears in the "Packages" section when it is not needed

Steps to reproduce:

1. Open or create a project
2. Go to "Window" ->"Package Management" -> "Package Manager"
3. Search for the "PSD"
4. Select the "2D PSD Importer" package
5. Click "Manage" in the details window
6. Click "Remove"
7. Observe the Packages section UI
8. Click "Install"
9. And again, observe the UI in the same section

Actual results: Scrollbar appears when it is not needed

Expected results: No scrollbar

Reproducible with versions: 6000.0.63f1, 6000.2.12f1, 6000.3.0f1, 6000.4.0a5, 6000.5.0a2

Tested on (OS): macOS - Tahoe  26.1