NPU attention refactor for FLUX (#12209)
* NPU attention refactor for FLUX transformer
* Apply style fixes
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Co-authored-by: J石页 <jiangshuo9@h-partners.com>
Co-authored-by: Aryan <aryan@huggingface.co>
Co-authored-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>
