Crash on Material::SetTextureInternal when heightmap resolution 4097 exceeds maxRenderTextureSize in Headless mode

Reproduction steps:

1. Open the attached “IN-151812” project
2. Make sure package issues are resolved
3. Close the Editor
4. Open a terminal at the project root
5. Run the “run_addressables_repro.sh” script
6. Observe the test results in the Terminal

Actual Result: A crash of the editor occurs
Expected Result: A crash of the editor would not occur, and the situation of a non power of two value would be handled gracefully

Reproducible with: 6000.0.81f1, 6000.3.22f1, 6000.5.7f1, 6000.6.0b10

Reproducible environments: macOS 15.7.7, macOS 26.6.1
Not reproducbile environments: No other environments tested

First few lines of the stacktrace:
1) <unknown>
2) Material::SetTextureInternal(ShaderLab::FastPropertyName, Texture const*, bool)
3) SplatMaterials::Update(Material*, SplatMaterialData const&, fixed_array<Terrain const*, 9ul> const&, TerrainData const&, bool)
4) Terrain::UpdateSplatMaterials(fixed_array<Terrain const*, 9ul> const&)
5) Terrain::AddToManager()
6) Terrain::AwakeFromLoad(AwakeFromLoadMode)

Notes:

• Only reproducible in Headless mode (-nographics)
• Terrains ‘Draw Instanced’ setting must be enabled