fix: TypeError when passing timezone-aware datetime to until()

[koteshyelamati]

Bug

Passing a timezone-aware datetime to job.until() raises TypeError: can't compare offset-naive and offset-aware datetimes in two places:

1. The past-time validation in until() compares self.cancel_after (aware) against datetime.datetime.now() (naive).
2. _is_overdue() compares the naive when argument against the aware self.cancel_after.

Reproduction

import schedule
import datetime
from zoneinfo import ZoneInfo

tz = ZoneInfo('America/New_York')
future = datetime.datetime.now(tz) + datetime.timedelta(hours=1)

# Raises TypeError: can't compare offset-naive and offset-aware datetimes
schedule.every(10).minutes.until(future).do(lambda: None)

Fix

• In until(): compare against datetime.datetime.now(tz=self.cancel_after.tzinfo) when cancel_after is timezone-aware.
• In _is_overdue(): localize the naive when via astimezone() before comparing, when cancel_after carries tzinfo.