Steps to reproduce:
1. Create new Unity project
2. Open Build Profiles window
3. Add Build Profile
4. Press “Add Settings” button and add Graphics Settings
5. Scroll down to find “Shader Settings”
6. Press “Save to asset...” button
7. Save New Shader Variants
8. Press “Save to asset...” button again

Actual results: user is allowed to save identical Shader Variants without changing the name, no pop-up is thrown, informing about already existing file
Expected results: Pop-up stating “NewShaderVariants.shadervariants” already exists. Do you want to replace it?” is thrown to the user

Reproducible with versions: 6000.0.67f1, 6000.3.10f1, 6000.4.0b9, 6000.5.0a7

Tested on (OS): Ubuntu 24.04

Notes:

•  on 6000.0.67f1, 6000.3.10f1 Shader Settings are in Project Settings > Graphics.