[3.12] gh-127190: Fix local_setattro() error handling (GH-127366) (#127368)

gh-127190: Fix local_setattro() error handling (GH-127366)

Don't make the assumption that the 'name' argument is a string. Use
repr() to format the 'name' argument instead.
(cherry picked from commit 20657fbdb14d50ca4ec115da0cbef155871d8d33)

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