An unused separation line is present in the Quality Settings list's dropdown menu when there is only one option to choose from in the Build Profiles Window

Steps to reproduce:

1. Open any Project
2. Navigate to File > Build Profiles
3. Create a custom Profile
4. Click "Add Settings" and choose "Quality Settings"
5. In the reorderable Quality Levels list add all available items when you press the "+" button
6. Click it one last time and observe the dropdown menu that appears

Actual results: An unused separation line is present at the top of the dropdown list when there are no more Quality Levels to add

Expected results: Separation Line is not shown when only 1 option is available in a dropdown menu

Reproducible with versions: 6000.3.11f1, 6000.4.0b11, 6000.5.0a8

Can’t test with versions: 6000.0.71f1

Tested on (OS): Windows 11