[Rebase] Rebase to vllm 0.27.0 (#5976)

Signed-off-by: tzhouam <tzhouam@connect.ust.hk>
Co-authored-by: Claude Opus 5 (1M context) <noreply@anthropic.com>

vllm_omni/quantization/bitsandbytes_config.py

@@ -20,7 +20,6 @@ from vllm.model_executor.layers.quantization.base_config import (
     QuantizationConfig,
     QuantizeMethodBase,
 )
-from vllm.model_executor.layers.quantization.fp8 import _copy_missing_attrs
 from vllm.model_executor.layers.quantization.utils.quant_utils import (
     is_layer_skipped,
 )
@@ -29,6 +28,9 @@ from vllm.model_executor.parameter import ModelWeightParameter
 from vllm.model_executor.utils import replace_parameter
 
 from vllm_omni.platforms import current_omni_platform
+from vllm_omni.quantization._copy_missing_attrs import (
+    copy_missing_attrs as _copy_missing_attrs,
+)
 from vllm_omni.quantization.int8_config import LazyWeightMixin
 
 if TYPE_CHECKING: