[Bugfix] Print warnings related to mistral_common tokenizer only on…

…ce (vllm-project#9468)

vllm/entrypoints/chat_utils.py

@@ -33,6 +33,7 @@
                                    async_get_and_parse_image,
                                    get_and_parse_audio, get_and_parse_image)
 from vllm.transformers_utils.tokenizer import AnyTokenizer, MistralTokenizer
+from vllm.utils import print_warning_once
 
 logger = init_logger(__name__)
 
@@ -564,14 +565,14 @@ def apply_mistral_chat_template(
     **kwargs: Any,
 ) -> List[int]:
     if chat_template is not None:
-        logger.warning(
+        print_warning_once(
             "'chat_template' cannot be overridden for mistral tokenizer.")
     if "add_generation_prompt" in kwargs:
-        logger.warning(
+        print_warning_once(
             "'add_generation_prompt' is not supported for mistral tokenizer, "
             "so it will be ignored.")
     if "continue_final_message" in kwargs:
-        logger.warning(
+        print_warning_once(
             "'continue_final_message' is not supported for mistral tokenizer, "
             "so it will be ignored.")