Install PyTorch without numpy constraint then downgrade numpy

Co-authored-by: aclegg3 <1445143+aclegg3@users.noreply.github.com>

Author: Copilot

.github/actions/install_ubuntu_deps/action.yml

@@ -50,10 +50,11 @@ runs:
     run: |-
       echo "Install conda and dependencies"
       # PyTorch 1.12.1 is pinned for CUDA 11.3 compatibility with habitat-sim
-      # Install PyTorch FIRST with all its dependencies (including MKL with ITT API)
-      # This ensures PyTorch gets the correct MKL version it was built against
-      conda install -y pytorch==1.12.1 torchvision==0.13.1 "numpy<2.0" -c pytorch -c nvidia
-      # Install remaining conda packages, avoid touching PyTorch/NumPy
+      # Install PyTorch FIRST without numpy constraint to get all its dependencies (including MKL with ITT API)
+      conda install -y pytorch==1.12.1 torchvision==0.13.1 -c pytorch -c nvidia
+      # Downgrade numpy if needed to ensure NumPy 1.x (PyTorch 1.12.1 requires NumPy 1.x)
+      conda install -y --force-reinstall "numpy<2.0" -c conda-forge
+      # Install remaining conda packages
       conda install -y -c conda-forge ninja pytest pytest-cov ccache hypothesis pytest-mock
       # Pin opencv-python to version compatible with NumPy 1.x (opencv 4.10.0.84 is last before NumPy 2.x requirement)
       # PyTorch 1.12.1 requires NumPy 1.x for proper symbol resolution (iJIT_NotifyEvent)