Remove wrong internal assert in handle_view_on_rebase (#88243)
Fixes: https://github.com/pytorch/pytorch/issues/88205
The `CreationMeta::NO_GRAD_MODE` path in handle_view_on_rebase wrongly assumes that the tensor would be a leaf, because tensors created in no_grad are always leaf tensors. However, due to creation_meta propagation, a view of a view created in no_grad also has `CreationMeta::NO_GRAD_MODE`, but DOES have grad_fn.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/88243
Approved by: https://github.com/albanD
