[ONNX] Update sum symbolic to handle dtypes (#64289) (#66141)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/66141
* Update aten::sum symbolic for dtype
* Remove nesting and modify opeartor tests
* Fix expect files
[ONNX] Fix expect files added in #64289 (#65356)
Test Plan: Imported from OSS
Reviewed By: jansel
Differential Revision: D31424091
fbshipit-source-id: d4af21e9f0d7e1c68bf6ef2f3e385db84b4c53f3
