### Godot version

0810ecaafdbee3ea747219e6ab3a8de5d2216a09

### System information

Windows 11, Nvidia 3000, firefox

### Issue description

Exporting the gltf file is corrupt in blender.

### Steps to reproduce

1. Open project.
2. Export as glb
3. Open in blender
4. Blender display many warnings

![image](https://user-images.githubusercontent.com/32321/216740742-de662c5c-f5c3-44b5-a36e-8ad33defdbba.png)


### Minimal reproduction project

https://cdn.discordapp.com/attachments/598003845657788438/1071249610896580691/Test_Game_Project.zip


Array cells = p_grid_map->get_used_cells();
	for (int32_t k = 0; k < cells.size(); k++) {
		GLTFNode *new_gltf_node = memnew(GLTFNode);
		p_gltf_node->children.push_back(p_state->nodes.size());
		p_state->nodes.push_back(new_gltf_node);
		Vector3 cell_location = cells[k];
		int32_t cell = p_grid_map->get_cell_item(
				Vector3(cell_location.x, cell_location.y, cell_location.z));
		Transform3D cell_xform;
		cell_xform.basis = p_grid_map->get_basis_with_orthogonal_index(
				p_grid_map->get_cell_item_orientation(
						Vector3(cell_location.x, cell_location.y, cell_location.z)));
		cell_xform.basis.scale(Vector3(p_grid_map->get_cell_scale(),
				p_grid_map->get_cell_scale(),
				p_grid_map->get_cell_scale()));
		cell_xform.set_origin(p_grid_map->map_to_local(
				Vector3(cell_location.x, cell_location.y, cell_location.z)));
		Ref<GLTFMesh> gltf_mesh;
		gltf_mesh.instantiate();
		gltf_mesh->set_mesh(_mesh_to_importer_mesh(p_grid_map->get_mesh_library()->get_item_mesh(cell)));
		new_gltf_node->mesh = p_state->meshes.size();
		p_state->meshes.push_back(gltf_mesh);
		new_gltf_node->xform = cell_xform * p_grid_map->get_transform();
		new_gltf_node->set_name(_gen_unique_name(p_state, p_grid_map->get_mesh_library()->get_item_name(cell)));
	}
}
#endif 
void GLTFDocument::_convert_multi_mesh_instance_to_gltf(