fix: update pr-test-sgl-kernel (#5399)

.github/workflows/pr-test-sgl-kernel.yml

@@ -44,12 +44,6 @@ jobs:
             cuda-version: '12.8'
     name: Build Wheel (CUDA ${{ matrix.cuda-version }})
     steps:
-      - name: Skip unnecessary builds on push to main
-        if: github.event_name == 'push' && (matrix.cuda-version == '11.8' || matrix.cuda-version == '12.8')
-        run: |
-          echo "Skipping CUDA ${{ matrix.cuda-version }} build on push to main"
-          exit 0
-
       - name: Cleanup
         run: |
           sudo rm -rf $GITHUB_WORKSPACE/* || true
@@ -64,6 +58,7 @@ jobs:
           python-version: ${{ matrix.python-version }}
 
       - name: Build wheel for Python ${{ matrix.python-version }} and CUDA ${{ matrix.cuda-version }}
+        if: github.event_name != 'push' || (matrix.cuda-version != '11.8' && matrix.cuda-version != '12.8')
         run: |
           cd sgl-kernel
           chmod +x ./build.sh