gh-105376: Restore deprecated logging warn() method (#122775) This reverts commit dcc028d92428bd57358a5028ada2a53fc79fc365 and commit 6c54e5d72166d012b52155cbf13af9e533290e06. Keep the deprecated logging warn() method in Python 3.13. Co-authored-by: Gregory P. Smith <greg@krypto.org> Co-authored-by: Hugo van Kemenade <1324225+hugovk@users.noreply.github.com>