Steps to reproduce:
1. Open any Project with Cinemachine Installed
2. In a Scene's Hierarchy create a Cinemachine Camera and select it
3. In the Inspector, open the "Palette..." dropdown menu and observe the options
Actual results: When a Palette Asset is not assigned, an unused separation line at the top of the dropdown menu options is used around 80% of the time
Expected results: No unused separation line is used when there are no options to separate
Reproducible with versions: 3.1.4 (6000.0.57f1, 6000.1.16f1, 6000.2.4f1, 6000.3.0b2)
Tested on (OS): Windows 11