Double separation lines are present in a kebab dropdown menu

Steps to reproduce:

1. Open any Project
2. Navigate to Window > Search > New Window
3. Open the kebab menu on the right of the Search Window
4. Observe the dropdown menu

Actual results: The dropdown menu contains double separation lines

Expected results: No double separation lines should be present

Reproducible with versions: 2023.3.0b1, 6000.0.8f1

Not reproducible with versions: 2021.3.40f1, 2022.3.35f1, 2023.2.20f1, 2023.3.0a23

Tested on (OS): Windows 11, macOS Sonoma

Notes:

• Issue appeared after the New Context Menu was pulled from trunk