use cpu version for testing

.github/workflows/test.yml

@@ -18,6 +18,6 @@ jobs:
       with:
         python-version: ${{ matrix.python-version }}
     - name: Install Dependencies
-      run: pip install torch && pip install -e '.[testing]'
+      run: pip install torch --index-url https://download.pytorch.org/whl/cpu && pip install -e '.[testing]'
     - name: Run Pytest
       run: python -m pytest -s -v