Fix attribute error in `isaac_patch_hf_runner` (#37685)

Signed-off-by: Harry Mellor <19981378+hmellor@users.noreply.github.com>
(cherry picked from commit 9f6d9dd3)

tests/models/multimodal/generation/vlm_utils/model_utils.py

@@ -24,6 +24,7 @@ from transformers import (
     GenerationConfig,
     GenerationMixin,
 )
+from transformers.masking_utils import create_causal_mask
 from transformers.video_utils import VideoMetadata
 
 from vllm.logprobs import SampleLogprobs
@@ -679,9 +680,13 @@ def isaac_patch_hf_runner(hf_model: HfRunner) -> HfRunner:
         sin = sin.to(inputs_embeds.dtype)
 
         # Prepare attention mask
-        if attention_mask is not None:
-            attention_mask = self._update_causal_mask(
-                attention_mask, inputs_embeds, cache_position, past_key_values, False
+        attention_mask = create_causal_mask(
+            config=self.config,
+            input_embeds=inputs_embeds,
+            attention_mask=attention_mask,
+            past_key_values=past_key_values,
+            position_ids=position_ids,
+            cache_position=cache_position,
         )
 
         # Initialize and collect hidden states