[Chore] Remove Sampler from Model Code (#17084)

Signed-off-by: Woosuk Kwon <woosuk.kwon@berkeley.edu>

vllm/model_executor/models/mamba2.py

@@ -19,7 +19,6 @@ from vllm.model_executor.layers.mamba.mamba_mixer2 import (
     MambaMixer2, extra_groups_for_head_shards)
 from vllm.model_executor.layers.quantization.base_config import (
     QuantizationConfig)
-from vllm.model_executor.layers.sampler import SamplerOutput, get_sampler
 from vllm.model_executor.layers.vocab_parallel_embedding import (
     DEFAULT_VOCAB_PADDING_SIZE, ParallelLMHead, VocabParallelEmbedding)
 from vllm.model_executor.model_loader.weight_utils import default_weight_loader
@@ -208,7 +207,6 @@ class Mamba2ForCausalLM(nn.Module, HasInnerState, IsAttentionFree,
 
         self.logits_processor = LogitsProcessor(self.unpadded_vocab_size,
                                                 config.vocab_size)
-        self.sampler = get_sampler()
 
         self.make_empty_intermediate_tensors = (
             self.backbone.make_empty_intermediate_tensors)
@@ -282,14 +280,6 @@ class Mamba2ForCausalLM(nn.Module, HasInnerState, IsAttentionFree,
                                        sampling_metadata)
         return logits
 
-    def sample(
-        self,
-        logits: Optional[torch.Tensor],
-        sampling_metadata: SamplingMetadata,
-    ) -> Optional[SamplerOutput]:
-        next_tokens = self.sampler(logits, sampling_metadata)
-        return next_tokens
-
     def load_weights(self, weights: Iterable[Tuple[str,
                                                    torch.Tensor]]) -> Set[str]:
         params_dict = dict(self.named_parameters())