[Bugfix][Minor] Make ignore_eos effective (vllm-project#4468)

Author: bigPYJ1151

vllm/sampling_params.py

@@ -275,7 +275,8 @@ def update_from_generation_config(
             self, generation_config: Dict[str, Any]) -> None:
         """Update if there are non-default values from generation_config"""
         # Update eos_token_id for generation
-        if eos_ids := generation_config.get("eos_token_id"):
+        if (not self.ignore_eos) and (eos_ids :=
+                                      generation_config.get("eos_token_id")):
             # it can be either int or list of int
             if isinstance(eos_ids, int):
                 eos_ids = [eos_ids]