Add Apple Silicon (MPS) support

[rbourgeat]

Issue: #5

This MR enables the TripoSG project to run on Apple Silicon (macOS) using PyTorch's MPS backend.

How to Run on macOS (Apple Silicon):

1. Enable MPS Fallback (Important):
   Before running any inference script, execute the following in your terminal:

export PYTORCH_ENABLE_MPS_FALLBACK=1

This is required because some 3D operations used during mesh extraction (e.g., max_pool3d_with_indices) are not yet natively supported on MPS and need to fall back to the CPU.

2. Example: Image-to-3D Inference:

python3 -m scripts.inference_triposg \
    --image-input assets/example_data/jkghed.png \ 
    --output-path ./output_macos_hierarchical.glb \
    --faces 5000 \
    --no-use-flash-decoder

(Note: --no-use-flash-decoder is recommended for MPS due to potential diso library compatibility and to ensure the CPU fallback path for hierarchical_extract_geometry (which now produces correct results with float32) is used.)

3. Example: Scribble-to-3D Inference:

python3 -m scripts.inference_triposg_scribble \
    --image-input assets/example_scribble_data/cat_with_wings.png \
    --prompt "a cat with wings" \
    --output-path ./output_macos_scribble.glb

[Stoobs]

How did you resolve the diso package not being available?

[prom3theu5]

They added a fallback in case diso isn't available in the PR, so you can comment it out
I also had to remove the version constraint from numpy, but it works then

Will be slower though as it falls back to the CPU for the final stage due to no DISO