gh-92886: make test_ast pass with -O (assertions off) (GH-98058)

-O does not strip docstrings.

Automerge-Triggered-By: GH:iritkatriel
(cherry picked from commit 27ce45d8)

Co-authored-by: Irit Katriel <1055913+iritkatriel@users.noreply.github.com>