modeling_deepseek_v3: fix GenerationMixin warning

Fix GenerationMixin warning introduced by upgrading transformers to 4.51.3.

ktransformers/models/modeling_deepseek_v3.py

@@ -30,6 +30,7 @@ from torch.nn import BCEWithLogitsLoss, CrossEntropyLoss, MSELoss
 
 from transformers.activations import ACT2FN
 from transformers.cache_utils import Cache, DynamicCache, StaticCache
+from transformers.generation import GenerationMixin
 from transformers.modeling_attn_mask_utils import (
     AttentionMaskConverter,
     _prepare_4d_attention_mask,
@@ -1598,7 +1599,7 @@ class DeepseekV3Model(DeepseekV3PreTrainedModel):
 
         return causal_mask
 
-class DeepseekV3ForCausalLM(DeepseekV3PreTrainedModel):
+class DeepseekV3ForCausalLM(DeepseekV3PreTrainedModel, GenerationMixin):
     _tied_weights_keys = ["lm_head.weight"]
 
     def __init__(self, config):