Fix instance uniforms breaking when setting a new mesh.

Fixes #58113

servers/rendering/renderer_scene_cull.cpp

@@ -653,6 +653,7 @@ void RendererSceneCull::instance_set_base(RID p_instance, RID p_base) {
 				geom->geometry_instance->set_use_baked_light(instance->baked_light);
 				geom->geometry_instance->set_use_dynamic_gi(instance->dynamic_gi);
 				geom->geometry_instance->set_use_lightmap(RID(), instance->lightmap_uv_scale, instance->lightmap_slice_index);
+				geom->geometry_instance->set_instance_shader_uniforms_offset(instance->instance_allocated_shader_uniforms_offset);
 				geom->geometry_instance->set_cast_double_sided_shadows(instance->cast_shadows == RS::SHADOW_CASTING_SETTING_DOUBLE_SIDED);
 				if (instance->lightmap_sh.size() == 9) {
 					geom->geometry_instance->set_lightmap_capture(instance->lightmap_sh.ptr());