[3.13] gh-146056: Fix repr() for lists containing NULLs (GH-146129) (GH-146155) (GH-146271)

(cherry picked from commit 0f2246b1553f401da5ade47e0fd1c80ad7a8dfa5)
(cherry picked from commit 796513306fdc1184452ea644b485f83511f39528)

Co-authored-by: Victor Stinner <vstinner@python.org>