Add logprobs mode in api stability test.

Signed-off-by: Wangshanshan <[email protected]>

Author: dominicshanshan

tensorrt_llm/sampling_params.py

@@ -181,7 +181,7 @@ class SamplingParams:
 
         logprobs (int, optional): Number of log probabilities to return per output token. Defaults to None.
         prompt_logprobs (int, optional): Number of log probabilities to return per prompt token. Defaults to None.
-        logprobs_mode (str): Controls return logprobs after sampling modifications. Defaults to "processed_logprobs".
+        logprobs_mode (Literal['processed_logprobs']): Controls return logprobs after sampling modifications. Defaults to "processed_logprobs".
             Options:
             - "processed_logprobs": Return log-softmax of processed logits
         return_context_logits (bool): Controls if Result should contain the context logits. Defaults to False.

tests/unittest/api_stability/references/sampling_params.yaml

@@ -15,5 +15,8 @@ methods:
       prompt_ignore_length:
         annotation: Optional[int]
         default: null
+      logprobs_mode:
+        annotation: Literal['processed_logprobs']
+        default: processed_logprobs
     return_annotation: None
 properties: {}