[3.13] gh-121977: Add tips for handling unhashable data (GH-122075) (#122076)

gh-121977: Add tips for handling unhashable data (GH-122075)
(cherry picked from commit ebc18abbf34ff248764bda1a02db7f1c783b71e3)

Co-authored-by: Raymond Hettinger <rhettinger@users.noreply.github.com>
1 file changed