[Bugfix] Update Florence-2 tokenizer to make grounding tasks work (#16734)

Signed-off-by: Isotr0py <2037008807@qq.com>

tests/conftest.py

@@ -925,6 +925,7 @@ class VllmRunner:
         max_tokens: int,
         num_logprobs: int,
         num_prompt_logprobs: Optional[int] = None,
+        skip_special_tokens: bool = True,
     ) -> Union[list[TokensTextLogprobs],
                list[TokensTextLogprobsPromptLogprobs]]:
         greedy_logprobs_params = SamplingParams(
@@ -932,6 +933,7 @@ class VllmRunner:
             max_tokens=max_tokens,
             logprobs=num_logprobs,
             prompt_logprobs=(num_prompt_logprobs),
+            skip_special_tokens=skip_special_tokens,
         )
         '''
         Greedy logprobs generation for vLLM encoder/decoder models