Upstream bug in `transformers` breaks use of `AutoModelForMaskGeneration` class to load SAM models
Simple fix - directly load the model with `SamModel` class instead.
See upstream issue https://github.com/huggingface/transformers/issues/38228
The validation on this node causes graph validation to valid. It must be validated _after_ instantiation.
Also, it was a bit too strict. The only case we explicitly do not handle is when both bboxes and points are provided. It's acceptable if neither are provided.
Closes#7248