adjust build reqs

.github/workflows/build.yml

@@ -25,7 +25,8 @@ jobs:
         run: |
           python -m pip install --upgrade pip
           pip install flake8 pytest Cython
-          pip install torch torch_geometric tensorflow dgl
+          pip install torch --index-url https://download.pytorch.org/whl/cpu
+          pip install torch_geometric tensorflow-cpu dgl
           if [ -f requirements.txt ]; then pip install -r requirements.txt; fi
       - name: Test with pytest
         run: |