fix: use setup.py install for CUTLASS extension build

tests/run_test.sh

@@ -35,7 +35,7 @@ pip install -e . --no-build-isolation -q
 # Build the CUTLASS NVFP4 GEMM C++ extension
 echo "       Building CUTLASS C++ extension..."
 cd "$REPO_DIR/src/nvfp4_megamoe_kernel/cutlass_nvfp4_gemm"
-pip install -e . --no-build-isolation -q
+python setup.py install
 
 # 4. Run the test
 echo "[4/4] Running layer test..."