Update generation_config.json

ref to https://huggingface.co/openai/gpt-oss-120b/blob/main/generation_config.json

generation_config.json

@@ -3,8 +3,9 @@
   "do_sample": true,
   "eos_token_id": [
     200002,
-    199999
+    199999,
+    200012
   ],
   "pad_token_id": 199999,
-  "transformers_version": "4.55.0"
-}
+  "transformers_version": "4.55.0.dev0"
+}