ENH: Add PyTorch dependency to SlicerDMRI

The TractCloud module in SlicerDMRI now requires PyTorch for
deep learning-based tractography parcellation. Adding PyTorch
as a build dependency ensures the PyTorchUtils extension is
installed, which handles correct CUDA/CPU wheel selection.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: 2 people

SlicerDMRI.json

@@ -1,7 +1,8 @@
 {
   "$schema": "https://raw.githubusercontent.com/Slicer/Slicer/main/Schemas/slicer-extension-catalog-entry-schema-v1.0.2.json#",
   "build_dependencies": [
-    "UKFTractography"
+    "UKFTractography",
+    "PyTorch"
   ],
   "build_subdirectory": "inner-build",
   "category": "Diffusion",