[Test] fix conv lowering test

tests/transformation/test_conv_lowering.py

@@ -37,6 +37,7 @@ from finn.transformation.fold_constants import FoldConstants
 from finn.transformation.infer_shapes import InferShapes
 from finn.util.test import get_test_model_trained
 from finn.transformation.lower_convs_to_matmul import LowerConvsToMatMul
+from finn.transformation.double_to_single_float import DoubleToSingleFloat
 import finn.core.onnx_exec as oxe
 
 export_onnx_path = "test_output_cnv.onnx"
@@ -46,6 +47,7 @@ def test_conv_lowering_cnv_w1a1():
     cnv = get_test_model_trained("CNV", 1, 1)
     bo.export_finn_onnx(cnv, (1, 3, 32, 32), export_onnx_path)
     model = ModelWrapper(export_onnx_path)
+    model = model.transform(DoubleToSingleFloat())
     model = model.transform(InferShapes())
     model = model.transform(FoldConstants())
     fn = pk.resource_filename("finn", "data/cifar10/cifar10-test-data-class3.npz")