Customizable toolbar Quality Level shows a deleted Quality Level as in use when the Quality Level is deleted in Project Settings

Steps to reproduce:

1. Create a new Unity project using the Universal 3D template
2. Click on the Quality Level button in the customizable toolbar
3. Select Open Quality Settings
4. Create 2 new Quality Levels
5. Click to switch to the Level 2 Quality Level in the Project Settings window
6. Delete the Level 2 Quality Level
7. Close the Project Settings window
8. Observe the Quality Level button in the customizable toolbar

Actual results: The Quality Level selected is still shown as Level 2

Expected results: The Quality Level is updated after deleting

Reproducible with versions: 6000.3.0b3, 6000.4.0a1

Can’t test with versions: 2022.3.67f1, 6000.0.58f1, 6000.2.6f1 (due to no customizable toolbar)

Tested on (OS): Ubuntu 24.04, macOS Silicon Sequoia 15.6.1

Notes:

• The issue fixes itself after opening on the Customizable toolbar's Quality Level dropdown and closing it