Unnecessary shader variants caused by the same keyword when declared in both multi_compile and shader_feature_local

How to reproduce:
1. Open the attached project "ShaderGraphMixedKeywords.zip"
2. Select Assets/Shaders/Simple.shader
3. Click on the "Compile and show code" dropdown in the Inspector window

Expected results: "Assets/Shaders/Simple.shader" generates 3 shader variants
Actual results: "Assets/Shaders/Simple.shader" generates 6 shader variants

Reproducible with: 2021.3.32f1, 2022.3.13f1, 2023.1.20f1, 2023.2.0b18, 2023.3.0a14

Reproducible on: Windows 11 22H2
Not reproducible on: No other environment tested