Fix _PyTraceMalloc_Fini() definition (GH-16259) (GH-16278)

The function return type is void, not int.
(cherry picked from commit d299b8b47d9dbea8fec2c2abcb6c32ad32f5f4d1)

Co-authored-by: Victor Stinner <vstinner@redhat.com>
1 file changed