[3.13] gh-120384: Fix array-out-of-bounds crash in `list_ass_subscript` (GH-120442) (#120826)

gh-120384: Fix array-out-of-bounds crash in `list_ass_subscript` (GH-120442)
(cherry picked from commit 8334a1b55c93068f5d243852029baa83377ff6c9)

Co-authored-by: Nikita Sobolev <mail@sobolevn.me>