How to reproduce:
1. Create a new project
2. Open the Package Manager Window
3. Open the “Unity Registry“ in the Package Manager
4. Dock the Package Manager Window on a panel that is horizontally smaller than the default layout of the Package Manager
5. Observe the Package Manager tab

Expected results: The “Install“ button is visible and accessible regardless of the tab size
Actual results: The “Install“ button is not visible and is not accessible when the tab is horizontally smaller than the default Package Manager layout

Reproducible in: 2021.3.38f1, 2022.3.30f1, 2023.2.0a23
Not reproducible in: 6000.0.2f1 (Horizontal scroll bar)
Fixed in: 2023.3.0a2 (a horizontal scroll bar was introduced)

Reproduced on: Windows 11 Pro (23H2)
Not reproduced on: No other environment tested