Updates Gemma3n MLP layer to adapt latest transformers version (#7573)

Signed-off-by: Xinyuan Tong <justinning0323@outlook.com>

python/sglang/srt/models/gemma3n_causal.py

@@ -62,7 +62,7 @@ class Gemma3nTextScaledWordEmbedding(Gemma3TextScaledWordEmbedding):
     pass
 
 
-class Gemma3nMLP(nn.Module):
+class Gemma3nTextMLP(nn.Module):
     def __init__(
         self,
         hidden_size: int,
@@ -514,10 +514,11 @@ class Gemma3nDecoderLayer(nn.Module):
             prefix=add_prefix("self_attn", prefix),
         )
 
+        intermediate_size = config.intermediate_size[layer_id]
         activation_sparsity = config.activation_sparsity_pattern[layer_id]
-        self.mlp = Gemma3nMLP(
+        self.mlp = Gemma3nTextMLP(
             hidden_size=self.hidden_size,
-            intermediate_size=config.intermediate_size,
+            intermediate_size=intermediate_size,
             hidden_activation=config.hidden_activation,
             activation_sparsity=activation_sparsity,
             quant_config=quant_config,