A few tests require downloading models. Skip those.

diff --git a/onnx/backend/test/runner/__init__.py b/onnx/backend/test/runner/__init__.py
index 5b60e7c0..838c7ba5 100644
--- a/onnx/backend/test/runner/__init__.py
+++ b/onnx/backend/test/runner/__init__.py
@@ -236,6 +236,7 @@ class Runner:
             print(
                 f"Start downloading model {model_test.model_name} from {model_test.url}"
             )
+            raise unittest.SkipTest('Skipping download')
             urlretrieve(model_test.url, download_file.name)
             print("Done")
             with tarfile.open(download_file.name) as t: