eevee_geom_world_vert.glsl and eevee_geom_volume_vert.glsl do not support shadows, but the shader validation pipeline still compiles the shadow variant of these shaders. This results in the fragment shader reading from inputs that are not written to as vertex shader outputs. On the Intel Windows OpenGL driver, this leads to a shader linking failure. This PR avoids the issue by writing zeros to the interface variables when MAT_SHADOW is defined. Pull Request: https://projects.blender.org/blender/blender/pulls/147821