[3.12] gh-118235: Skip RAISE_SYNTAX_ERROR rules in the grammar spec (GH-118237) (GH-118309)

gh-118235: Skip RAISE_SYNTAX_ERROR rules in the grammar spec (GH-118237)
(cherry picked from commit ef940dec409f0a9e4f353c6188990aeb3ad4ffb4)

Co-authored-by: Petr Viktorin <encukou@gmail.com>