[Models]: Make Multimodal config implicit in ViT implementation (#31972)

Signed-off-by: Isotr0py <mozf@mail2.sysu.edu.cn>

vllm/model_executor/models/opencua.py

@@ -244,7 +244,6 @@ class OpenCUAForConditionalGeneration(Qwen2_5_VLForConditionalGeneration):
                 vision_config=config.vision_config,
                 norm_eps=getattr(config, "rms_norm_eps", 1e-6),
                 quant_config=self.quant_config,
-                multimodal_config=self.multimodal_config,
                 prefix=maybe_prefix(prefix, "visual"),
             )