bug fix in _construct_target_class()

**`BaseModel.parse_obj()`** appears to only need to get a dictionary as its argument, not **kwargs from the 'x' dictionary object

Author: RichardBruskiewich

linkml_runtime/loaders/loader_root.py

@@ -122,7 +122,7 @@ def _construct_target_class(self,
                if issubclass(target_class, YAMLRoot):
                    return [target_class(**as_dict(x)) for x in data_as_dict]
                elif issubclass(target_class, BaseModel):
-                   return [target_class.parse_obj(**as_dict(x)) for x in data_as_dict]
+                   return [target_class.parse_obj(as_dict(x)) for x in data_as_dict]
                else:
                    raise ValueError(f'Cannot load list of {target_class}')
             elif isinstance(data_as_dict, dict):
@@ -153,4 +153,4 @@ def _read_source(self,
         else:
             data = source
 
-        return data
+        return data