Asset import fails when importing the Shader Graph "Production Ready Shaders" sample

How to reproduce:
1. Create a new empty URP project
2. Open the Package Manager (Window → Package Manager)
3. In the “In Project” tab, select Shader Graph
4. Navigate to the “Samples” tab
5. Import the “Production Ready Shaders” sample
6. In the Project window, navigate to “Assets/Samples/Shader Graph/17.0.3/Production Ready Shaders/Lit”
7. Observe the “URPLit” shader

Expected result: The asset is imported correctly, showing a blue icon
Actual result: The icon appears white and when selected, the Inspector shows that import errors were generated

Reproducible in: 6000.0.19f1
Not reproducible in: 2022.3.46f1
Could not test with: 2021.3.43f1 (“Production Ready Shaders” sample does not exist)

Reproducible on: Windows 11
Not reproducible on: No other environments tested

Notes:

• Not a regression as the “Production Ready Shaders” sample was recently introduced (6000.0.5f1)
• The import errors (displayed in the Inspector) can be printed in the Console (see internal notes)