[ONNX] Refactor to remove inline imports - attempt 2 (#77448)
Re-land
- #77142
(diff: https://github.com/pytorch/pytorch/compare/c08b8f0..justinchuby:justinchu/remove-patch2)
Fixed:
- Delay import symbolic_opsets in the registry.
Tested locally with torchvision
Pull Request resolved: https://github.com/pytorch/pytorch/pull/77448
Approved by: https://github.com/garymm
