MODNet webcam portrait matting model, safetensors format

The model weights in model.safetensors are the official pre-trained MODNet webcam portrait matting
checkpoint (modnet_webcam_portrait_matting.ckpt) by Zhanghan Ke, Jiayu Sun, Kaican Li, Qiong Yan and
Rynson W.H. Lau, published at https://github.com/ZHKKKe/MODNet (commit
28165a451e4610c9d77cfdf925a94610bb2810fb). According to that repository's README, its code, models and demos
are released under the Apache License 2.0 (see LICENSE).

Modification: the checkpoint was converted from a PyTorch pickle to the safetensors format. All 751
state_dict entries keep their names and values. Tensors that the original checkpoint stores under two names
(module.backbone.* and module.lr_branch.backbone.*) are saved as two identical copies.