Actions: Update dependency install for CUDA

Used to use a non-existent variable.

Signed-off-by: kingbri <bdashore3@proton.me>

.github/workflows/build-wheels.yml

@@ -65,7 +65,7 @@ jobs:
           $cudaVersionPytorch = '${{ matrix.cuda }}'.Remove('${{ matrix.cuda }}'.LastIndexOf('.')).Replace('.','')
 
           mamba install -y -c nvidia/label/cuda-$cudaVersion cuda-toolkit cuda-runtime
-          if (!(mamba list cuda)[-1].contains('cuda')) {sleep -s 10; mamba install -y 'cuda' $cudaChannels.TrimEnd().Split()}
+          if (!(mamba list cuda)[-1].contains('cuda')) {sleep -s 10; mamba install -y 'cuda' $cudaVersion}
           if (!(mamba list cuda)[-1].contains('cuda')) {throw 'CUDA Toolkit failed to install!'}
           
           python -m pip install --upgrade build setuptools wheel packaging ninja torch==${{ matrix.torchver }} psutil --extra-index-url "https://download.pytorch.org/whl/cu121"