[Model] Re-add the implicit conversion feature for as_seq_cls_model (#21103)

Signed-off-by: wang.yuqi <noooop@126.com>

vllm/model_executor/models/llama.py

@@ -49,7 +49,6 @@ from vllm.model_executor.model_loader.weight_utils import (
 from vllm.model_executor.sampling_metadata import SamplingMetadata
 from vllm.sequence import IntermediateTensors
 
-from .adapters import as_seq_cls_model
 from .interfaces import SupportsLoRA, SupportsPP
 from .utils import (AutoWeightsLoader, PPMissingLayer, extract_layer_index,
                     is_pp_missing_parameter,
@@ -646,6 +645,3 @@ class LlamaForCausalLM(nn.Module, SupportsLoRA, SupportsPP):
                 name = name.replace(item, mapping[item])
 
         return name, loaded_weight
-
-
-LlamaForSequenceClassification = as_seq_cls_model(LlamaForCausalLM)