The scrollbar in the 2D Animation Asset Upgrader window does not scroll far enough to see all the content when the 2D Animation Asset Upgrader window is docked

Steps to reproduce:

1. Create a new Unity project using the Universal 2D template
2. Open the 2D Animation Asset Upgrader window (Window > 2D > 2D Animation Asset Upgrader)
3. Dock the 2D Animation Asset Upgrader window
4. Resize the 2D Animation Asset Upgrader window horizontally until a scrollbar at the bottom appears
5. Scroll with the scrollbar all the way to the left
6. Observe the buttons at the bottom of the 2D Animation Asset Upgrader window

Actual results: The "Scan Project" button is not visible even when the scrollbar is fully scrolled to the left

Expected results: All UI elements are visible

Reproducible with versions: 6000.0.67f1, 6000.3.9f1, 6000.4.0b9, 6000.5.0a7

Tested on (OS): MacOS Silicon Tahoe 26.2, Ubuntu 24.04