[Neuron] Enable `torch.compile` compatibility with Neuron device (#13485)
* draft:add neuron as a legit backend
* feat: neuron-specific changes in the pipeline
* tests: eager tests
* fix: style
* fix:apr_02 beta
* fix:pixart
* fix: rewrite flux swiglu activation to avoid gather op in neuron IR
* test: pixart compile mode on neuron
* cleanup & fix style
* test: flux2 klein and sdxl-turbo
* review: address some comments
* revert:put back expected slices
* cleanup:move the ts index ahead of denoising + cleanup tests
* fix: style
* fix style
* review:remove the hook
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Co-authored-by: Sayak Paul <spsayakpaul@gmail.com>