Overlay: Remove Unused Attribute in edit mesh face shader

`overlay_edit_mesh_face` has an attribute for its vertex normals,
but only used in the vertex shader when it isn't a face shader.

Removing this attribute fixes some performance validation warnings
in the Vulkan backend.

Pull Request: https://projects.blender.org/blender/blender/pulls/112269

source/blender/draw/engines/overlay/shaders/infos/overlay_edit_mode_info.hh

@@ -131,7 +131,6 @@ GPU_SHADER_CREATE_INFO(overlay_edit_mesh_face)
     .define("FACE")
     .vertex_in(0, Type::VEC3, "pos")
     .vertex_in(1, Type::UVEC4, "data")
-    .vertex_in(2, Type::VEC3, "vnor")
     .vertex_out(overlay_edit_flat_color_iface)
     .fragment_source("overlay_varying_color.glsl")
     .additional_info("overlay_edit_mesh_common");