Mask not showing up in onnx_model_example.ipynb point and box example

@HannaMao @ericmintun I am running the examples from: onnx_model_example.ipynb
And noticed that the last step which is point and box does not show the finalized mask. Even when loading the previous mask(s) the final result shows only a point and box but no mask. (Adding Python script )


[segment_ai_onxx_model.zip](https://github.com/facebookresearch/segment-anything/files/11182541/segment_ai_onxx_model.zip)

Start with onnx_model_example.ipynb and the attached Python script, then run the final point-and-box example and the previous-mask variant. Trace the visualization step that should display the finalized mask; done means both workflows show the mask along with the point and box.

Written by the indexing model from the issue text.