Fix import error

demo/mast3r_demo.py

@@ -25,6 +25,7 @@ from mast3r.cloud_opt.tsdf_optimizer import TSDFPostProcess
 from mast3r.model import AsymmetricMASt3R
 from dust3r.image_pairs import make_pairs
 from dust3r.utils.image import load_images
+from dust3r.utils.device import to_numpy
 from dust3r.viz import add_scene_cam, CAM_COLORS, OPENGL, pts3d_to_trimesh, cat_meshes
 from dust3r.demo import get_args_parser as dust3r_get_args_parser
 from copy import deepcopy