Improve Mistral format checks. (#33253)

Signed-off-by: Julien Denize <julien.denize@mistral.ai>
Signed-off-by: juliendenize <julien.denize@mistral.ai>
Co-authored-by: Michael Goin <mgoin64@gmail.com>

tests/conftest.py

@@ -365,6 +365,7 @@ class HfRunner:
             self.config,
             dtype=dtype,
             is_pooling_model=is_sentence_transformer or is_cross_encoder,
+            config_format="hf",
         )
 
         model_kwargs = model_kwargs if model_kwargs is not None else {}