Remove dim order check in unsqueeze op to unblock supernova model release (#5299)

Summary:
Pull Request resolved: https://github.com/pytorch/executorch/pull/5299

TLDR: recently introduced dim order check blocks supernova team from releasing the latest language model. This diff does a minimum revert to mitigate the issue and unblock the model release.

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Diving into the operator, the sanity checks themselves are correct, but the ambiguous dim order issue causes the problem. The size of input and output tensor of unsqueeze op are [1,1,768] and [1,1,1,768]. Our system interprets the first one as contiguous dim order while the second one as channels_last, which triggers the assertion failure.

To unblock the model releasing, I removed the dim order check in the unsqueeze op. In the long term, I need to figure out the way to solve the ambiguous dim order stuff.

Reviewed By: digantdesai, cccclai

Differential Revision: D62550036

fbshipit-source-id: 8aa9d6e58871a68d81a608534faeff22b695e51f