[3.14] gh-136517: Print uncollectable objects if DEBUG_UNCOLLECTABLE mode was set (GH-136518) (#136522)

gh-136517: Print uncollectable objects if DEBUG_UNCOLLECTABLE mode was set (GH-136518)
(cherry picked from commit c560df9658f1a24edea995fe6f9c84c55b37cfb3)

Co-authored-by: Sergey Miryanov <sergey.miryanov@gmail.com>