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 a new Quality Level
5. Enter a long name for the Quality Level
6. Repeat step 2
7. Switch to the newly created Quality Level with long name
8. Hold the Command key and and reorder the Quality Level button all the way to the left of the customizable toolbar
9. Observe the customizable toolbar

Actual results: The Quality Level button pushes all the other buttons out of view and is the width of the whole Editor

Expected results: There is a maximum width set to the Quality Level button so that it would not fully scale with the Quality Level name and push all the other buttons out of view and take the whole width of the Editor

Reproducible with versions: 6000.3.0a5

Tested on (OS): macOS Silicon Sequoia 15.5