[Relay][Testing][Bugfix] py_converter should use correct AST for ve…

…rsions above 3.8 too (apache#13635)

Currently, `relay.testing.py_converter` is checking for using _exactly_ Python 3.8 in order to use certain updated signatures in the `ast` library. However, those signatures are also correct for versions _above_ 3.8. This PR changes the bounds checks so that the converter will work above 3.8.

python/tvm/relay/testing/py_converter.py

@@ -88,7 +88,7 @@ def convert(self, prog: Expr):
         body.append(Assign([Name(OUTPUT_VAR_NAME, Store())], prog_body))
         global __MAJOR__, __MINOR__
 
-        if __MAJOR__ == 3 and __MINOR__ == 8:
+        if __MAJOR__ == 3 and __MINOR__ >= 8:
             return ast.fix_missing_locations(ast.Module(body=body, type_ignores=[]))
         else:
             return ast.fix_missing_locations(ast.Module(body=body))
@@ -224,7 +224,7 @@ def create_def(self, func_name: str, arguments: [str], body):
         inner_args = [ast.arg(argument, None) for argument in arguments]
 
         global __MAJOR__, __MINOR__
-        if __MAJOR__ == 3 and __MINOR__ == 8:
+        if __MAJOR__ == 3 and __MINOR__ >= 8:
             arguments = ast.arguments([], inner_args, None, [], [], None, [])
         else:
             arguments = ast.arguments(inner_args, None, [], [], None, [])