Fix syntax error in an example in the ast documentation and sync docstrings (GH-18946)

diff --git a/Doc/library/ast.rst b/Doc/library/ast.rst
index 45f16c1..fc04114 100644
--- a/Doc/library/ast.rst
+++ b/Doc/library/ast.rst
@@ -1704,7 +1704,7 @@
                   value=Name(id='data', ctx=Load()),
                   slice=Constant(value=node.id),
                   ctx=node.ctx
-              ), node)
+              )
 
    Keep in mind that if the node you're operating on has child nodes you must
    either transform the child nodes yourself or call the :meth:`generic_visit`