Added Quality levels get different index numbers than when renamed to an empty string

Steps to reproduce:

1. Create and open a new URP project
2. Open Edit -> Project Settings -> Quality
3. Add a new Level to the list
4. Delete the text from the name and press Enter
5. Observe the Quality Level name

Actual results: The number is lower by one than before deleting the text

Expected results: The number is the same as before deleting the text

Reproducible with versions: 6000.6.0a6

Not reproducible with versions: 6000.0.76f1, 6000.3.17f1, 6000.4.10f1, 6000.5.0b11, 6000.6.0a5

Tested on (OS): Windows 11 Pro (25H2)

Notes:

• If the newly created level number is 5, after deleting the text and pressing enter, the number will be 4 (this is true for any level).