tweak ds3 model.py to reflect main branch for DS3 baseline can run (#1684)

Author: bdhirsh

torchtitan/models/deepseek_v3/model/model.py

@@ -270,9 +270,7 @@ def __init__(self, layer_id: int, model_args: DeepSeekV3ModelArgs):
         self.attention = Attention(model_args)
         self.attention_norm = nn.RMSNorm(model_args.dim, eps=model_args.norm_eps)
         self.ffn_norm = nn.RMSNorm(model_args.dim, eps=model_args.norm_eps)
-        # self.moe_enabled = layer_id >= model_args.n_dense_layers
-        # TODO: enable me when local_map works
-        self.moe_enabled = False
+        self.moe_enabled = layer_id >= model_args.n_dense_layers
 
         if self.moe_enabled:
             self.moe = MoE(