[ONNX] Remove usage of isCompleteTensor() in symbolic functions (#48162)
Summary:
`isCompleteTensor()` only returns true when both scalar type and shape is present. All dimensions in the shape must be static. This high requirement is unnecessary for many use cases such as when only rank or scalar type needs to be known.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/48162
Reviewed By: malfet
Differential Revision: D25340823
Pulled By: bzinodev
fbshipit-source-id: 1fef61f44918f4339dd6654fb725b18cd58d99cf
