[skip ci] update cuda installation

.github/workflows/building.yml

@@ -46,17 +46,17 @@ jobs:
         run: |
           pip install torch==${{ matrix.torch-version}}+${{ matrix.cuda-version }} -f https://download.pytorch.org/whl/torch_stable.html
 
-      - Install main package for CPU:
-        if: ${{ matrix.cuda-version != 'cpu' }}
+      - name: Install main package for CPU:
+        if: ${{ matrix.cuda-version == 'cpu' }}
         run: |
-          source .github/workflows/cuda/${{ matrix.cuda-version }}-${{ runner.os }}-env.sh
-          FORCE_CUDA=1 pip install -e .
+          FORCE_ONLY_CPU=1 pip install -e .
           ls -lah torch_scatter/
 
-      - Install main package with CUDA:
-        if: ${{ matrix.cuda-version == 'cpu' }}
+      - name: Install main package with CUDA:
+        if: ${{ matrix.cuda-version != 'cpu' }}
         run: |
-          FORCE_ONLY_CPU=1 pip install -e .
+          source .github/workflows/cuda/${{ matrix.cuda-version }}-${{ runner.os }}-env.sh
+          FORCE_CUDA=1 pip install -e .
           ls -lah torch_scatter/
 
       - name: Build wheel