Enable TorchAO int4wo quantization tests on XPU (#13537)
* Enable TorchAO int4wo quantization tests on XPU
- Remove _int4wo_skip marker that restricted int4wo tests to CUDA only
- Add XPU-specific int4_packing_format='plain_int32' for Int4WeightOnlyConfig
* add xpu to not skip
Signed-off-by: jiqing-feng <jiqing.feng@intel.com>
* Apply style fixes
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Signed-off-by: jiqing-feng <jiqing.feng@intel.com>
Co-authored-by: Sayak Paul <spsayakpaul@gmail.com>
Co-authored-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>
