[Frontend] Make beam search emulator temperature modifiable (#8928)

Co-authored-by: Eduard Balzin <nfunctor@yahoo.fr>

vllm/entrypoints/llm.py

@@ -396,6 +396,7 @@ class LLM:
         beam_width: int,
         max_tokens: int,
         ignore_eos: bool = False,
+        temperature: float = 0.0,
     ) -> List[BeamSearchOutput]:
         """
         Generate sequences using beam search.
@@ -405,6 +406,7 @@ class LLM:
                 of token IDs.
             beam_width: The number of beams to keep at each step.
             max_tokens: The max number of tokens to generate for each prompt.
+            temperature: The temperature to use for generation.
         
         TODO: how does beam search work together with length penalty, frequency
         penalty, and stopping criteria, etc.?
@@ -416,7 +418,7 @@ class LLM:
         # at https://github.com/huggingface/transformers/blob/e15687fffe5c9d20598a19aeab721ae0a7580f8a/src/transformers/generation/beam_search.py#L534 # noqa
         beam_search_params = SamplingParams(logprobs=2 * beam_width,
                                             max_tokens=1,
-                                            temperature=0.0)
+                                            temperature=temperature)
         instances: List[BeamSearchInstance] = []
 
         for prompt in prompts: