Shader variants are stripped when they are not used during Player building

How to reproduce:

1. Open the attached “IN-144771_shader_variant_stripping_with_keep_all” project
2. “Build and Run” (File > Build profiles)
3. Open the “Player.log”
4. Inspect messages near the end of the log

Actual result: Messages about not found shader variants are present
Expected result: No messages about not found shader variants occur

Reproducible with: 6000.0.0f1, 6000.0.77f1, 6000.3.18f1, 6000.4.12f1, 6000.5.0f1, 6000.6.0a7

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

Notes:

• Reproducible when shader variant is requested at runtime but is not required at build time
• Reproducible with “Instancing Variants” - “Keep All” (Edit > Project Settings > Graphics > Shader Stripping)
• Reproducible when shader is assigned to “Always Included Shaders” (Edit > Project Settings > Graphics > Shader Settings)
• A few full warnings:
  Shader Repro/ProceduralInstancingVariantRepro, subshader 0, pass 0, stage vertex: variant PROCEDURAL_INSTANCING_ON not found.
  Shader Repro/ProceduralInstancingVariantRepro, subshader 0, pass 0, stage pixel: variant PROCEDURAL_INSTANCING_ON not found.