generation_config.json adds a mapping with the special token '<|im_end|>' to solve the problem of non-stop generation when <|im_end|> is encountered.

Using vllm to infer 'Llama3-ChatQA-1.5-8B', it will continue to be generated when encountering the special token '<|im_end|>', as shown in the figure below. This PR adds a mapping to '<|im_end|>' in the tokenizer.
At the same time, '<|im_end|>' needs to be configured in the tokenizer: https://huggingface.co/nvidia/Llama3-ChatQA-1.5-8B/discussions/16


generation_config.json

@@ -1,6 +1,6 @@
 {
   "_from_model_config": true,
   "bos_token_id": 128000,
-  "eos_token_id": [128001, 128009],
+  "eos_token_id": [128001, 128009, 128010],
   "transformers_version": "4.40.0.dev0"
 }