[3.13] gh-133881: add forward reference to `list.sort()` in lambda expression tutorial (GH-133910) (#134127)

gh-133881: add forward reference to `list.sort()` in lambda expression tutorial (GH-133910)
(cherry picked from commit c1c9ad1d5a62a591eb2f0f0d29f3fa02e0949f14)

Co-authored-by: Oleg Burnaev <51371645+Shepard2154@users.noreply.github.com>