[Announce] Move existing models (< opset_version 13) to models/legacy

Feature Request

What is the problem that this feature solves?

All of existing ONNX Model Zoo models use opset_version<13, which is a quite old version (opset 12 released on May 8, 2020 in ONNX 1.7.0). Please see similar discussion in https://github.com/onnx/models/issues/472. While we will bring more new models with higher opset_version (i.e., 18): https://github.com/onnx/models/issues/617, move existing old models to models/legacy for better awareness. Also the upload requirements/model storage structure will be changed.

Describe the feature

Why is this feature necessary? What does it accomplish?

• Move existing models (< opset_version 13) to models/legacy
• ONNX Hub will continue to support download these old models, but please note that the location of these models will be changed. (Moved to models legacy)
• In the future, once ONNX Model Zoo has sufficient new models, we will remove the legacy directory entirely and please go ahead to use higher opset_version instead.

Relevant Model Zoo feature areas

Which area in the Model Zoo infrastructure does this impact?
Feature Area (e.g. CI, file organization, model storage, other):
CI, file organization

Notes

Any additional information
If anyone has any question/concern, feel free to raise in this thread. Thank you for the contribution!

Start by inventorying the existing models and their opset versions, then review the models/legacy location and the ONNX Hub download references described in the issue. Done means models with opset_version below 13 are moved to models/legacy, while CI, file organization, and downloads continue to account for the new location.