Revert "Fix/onnx serde error workaround (#10422)"

This reverts commit dcc4a7a.

Author: akihironitta

CHANGELOG.md

@@ -8,7 +8,6 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/).
 ### Fixed
 
 - Fixed `ogbn_train_cugraph` example for distributed cuGraph ([#10439](https://github.com/pyg-team/pytorch_geometric/pull/10439))
-- Added `safe_onnx_export` function with workarounds for `onnx_ir.serde.SerdeError` issues in ONNX export ([#10422](https://github.com/pyg-team/pytorch_geometric/pull/10422))
 - Fixed importing PyTorch Lightning in `torch_geometric.graphgym` and `torch_geometric.data.lightning` when using `lightning` instead of `pytorch-lightning` ([#10404](https://github.com/pyg-team/pytorch_geometric/pull/10404), [#10417](https://github.com/pyg-team/pytorch_geometric/pull/10417)))
 - Fixed `detach()` warnings in example scripts involving tensor conversions ([#10357](https://github.com/pyg-team/pytorch_geometric/pull/10357))
 - Fixed non-tuple indexing to resolve PyTorch deprecation warning ([#10389](https://github.com/pyg-team/pytorch_geometric/pull/10389))

test/nn/models/test_basic_gnn.py

@@ -251,12 +251,10 @@ def test_packaging():
 @onlyLinux
 @withPackage('torch>=2.6.0')
 @withPackage('onnx', 'onnxruntime', 'onnxscript')
-def test_onnx(tmp_path: str) -> None:
+def test_onnx(tmp_path):
     import onnx
     import onnxruntime as ort
 
-    from torch_geometric import safe_onnx_export
-
     warnings.filterwarnings('ignore', '.*tensor to a Python boolean.*')
     warnings.filterwarnings('ignore', '.*shape inference of prim::Constant.*')
 
@@ -278,27 +276,17 @@ def forward(self, x, edge_index):
     assert expected.size() == (3, 16)
 
     path = osp.join(tmp_path, 'model.onnx')
-    success = safe_onnx_export(
+    torch.onnx.export(
         model,
         (x, edge_index),
         path,
         input_names=('x', 'edge_index'),
         opset_version=18,
         dynamo=True,  # False is deprecated by PyTorch
-        skip_on_error=True,  # Skip gracefully in CI if upstream issue occurs
     )
 
-    if not success:
-        # ONNX export was skipped due to known upstream issue
-        # This allows CI to pass while the upstream bug exists
-        warnings.warn(
-            "ONNX export test skipped due to known upstream onnx_ir issue. "
-            "This is expected and does not indicate a problem with PyTorch "
-            "Geometric.", UserWarning, stacklevel=2)
-        return
-
-    onnx_model = onnx.load(path)
-    onnx.checker.check_model(onnx_model)
+    model = onnx.load(path)
+    onnx.checker.check_model(model)
 
     providers = ['CPUExecutionProvider']
     ort_session = ort.InferenceSession(path, providers=providers)