Update config.json

add max_position_embeddings and set it to 128k.
(1024 * 128_000 =131_072_000)

config.json

@@ -20,6 +20,7 @@
         "head_dim": 128,
         "hidden_size": 5376,
         "intermediate_size": 21504,
+        "max_position_embeddings": 131072,
         "model_type": "gemma3_text",
         "num_attention_heads": 32,
         "num_hidden_layers": 62,