python:3.8-slim is EOL (security support ended Oct 2024). Move to
python:3.12-slim and drop the pinned setuptools==59.5.0, which
predates 3.12 support; use the current setuptools instead.
Without unbuffered output the bot's stdout/stderr can sit in a
buffer, so 'docker logs' shows nothing until the buffer flushes.
Set PYTHONUNBUFFERED=1 so log lines appear in real time.
Father Bot