pytz was a direct runtime dependency used in exactly one place: a 2017 data migration. Replace it with stdlib equivalents available since Python 3.9/3.11, eliminating the third-party dependency entirely.

Changes

• migrations/0002_auto_20170912_1346.py — swap pytz primitives for stdlib:
  • pytz.timezone(name) → ZoneInfo(name) (zoneinfo, stdlib since 3.9)
  • pytz.utc → UTC (datetime.UTC, stdlib since 3.11; project targets 3.12)
• pyproject.toml — remove pytz dependency
• poetry.lock — regenerated

# before
from pytz import timezone, utc
current_tz = timezone(settings.TIME_ZONE)
block.from_datetime = block.from_datetime.astimezone(current_tz).replace(tzinfo=utc)

# after
from datetime import UTC
from zoneinfo import ZoneInfo
current_tz = ZoneInfo(settings.TIME_ZONE)
block.from_datetime = block.from_datetime.astimezone(current_tz).replace(tzinfo=UTC)