[pytorch][coreml] Use from_blob instead of empty in pack_outputs (#96564)
Summary:
We don't want to load when loading model on Core ML and `at::empty` is considered an op.
So replace it with from_blob.
Test Plan:
Run Core ML backend to ensure it works for existing use cases.
Also test running Core ML backend without any ops.
Differential Revision: D43961679
Pull Request resolved: https://github.com/pytorch/pytorch/pull/96564
Approved by: https://github.com/f-meloni, https://github.com/kimishpatel
