[Python] fixes __setitem__ throwing an error for composed instance (#10197)

* adding a test for issues 10083

* commiting the generated files

* fix for the setattr issue

* commit generated files

Co-authored-by: Aanisha Mishra <[email protected]>

Author: vvb

.generator/templates/model_utils.mustache

@@ -1182,6 +1182,9 @@ def is_valid_type(input_class_simple, valid_classes):
     Returns:
         bool
     """
+    if issubclass(input_class_simple, OpenApiModel) and \
+        valid_classes == (bool, date, datetime, dict, float, int, list, str, none_type,):
+        return True
     valid_type = input_class_simple in valid_classes
     if not valid_type and (
             issubclass(input_class_simple, OpenApiModel) or