[3.10] bpo-34990: Treat the pyc header's mtime in compileall as an unsigned int (GH-19708)

(cherry picked from commit bb21e28fd08f894ceff2405544a2f257d42b1354)

Co-authored-by: Ammar Askar <ammar@ammaraskar.com>
Co-authored-by: Stéphane Wirtel <stephane@wirtel.be>
4 files changed