Fix invalid generation config

The latest transformers version rejects that configuration when trying to save the model. Since do_sample is False, neither temperature nor top_k should be set.

generation_config.json

@@ -3,7 +3,5 @@
   "bos_token_id": 1,
   "eos_token_id": 2,
   "pad_token_id": 32000,
-  "temperature": 0.9,
-  "top_p": 0.6,
   "transformers_version": "4.31.0.dev0"
 }