Fix add-new-model-like (#31773)

* handle (processor_class, None) returned by ModelPatterns

* handle (slow, fast) image processors in add model

* handle old image processor case

src/transformers/commands/add_new_model_like.py

@@ -761,7 +761,12 @@ def retrieve_info_for_model(model_type, frameworks: Optional[List[str]] = None):
         tokenizer_class = tokenizer_classes[0] if tokenizer_classes[0] is not None else tokenizer_classes[1]
     else:
         tokenizer_class = None
-    image_processor_class = auto_module.image_processing_auto.IMAGE_PROCESSOR_MAPPING_NAMES.get(model_type, None)
+    image_processor_classes = auto_module.image_processing_auto.IMAGE_PROCESSOR_MAPPING_NAMES.get(model_type, None)
+    if isinstance(image_processor_classes, tuple):
+        image_processor_class = image_processor_classes[0]  # we take the slow image processor class.
+    else:
+        image_processor_class = image_processor_classes
+
     feature_extractor_class = auto_module.feature_extraction_auto.FEATURE_EXTRACTOR_MAPPING_NAMES.get(model_type, None)
     processor_class = auto_module.processing_auto.PROCESSOR_MAPPING_NAMES.get(model_type, None)