Move GHA to ONNX (#65975)
Summary:
- Delete CircleCI ONNX config
- Add sharded ONNX job to the list of generated workflows
- Move ONNX runtime installation from `pytorch-job-specs.yml` to `.jenkins/caffe2/test.sh`
- Limit MKLDNN to AVX2 ISA while running Caffe2 tests
Pull Request resolved: https://github.com/pytorch/pytorch/pull/65975
Reviewed By: seemethere
Differential Revision: D31327206
Pulled By: malfet
fbshipit-source-id: 15aa53e4481e846c62b4ee2db5c03047d68679a4
