fix: use getattr for safe access to request.axes_attempt_time

[muhamedfazalps]

Summary

Fixes #1424

get_cool_off_threshold() declares request as Optional[HttpRequest] with a default of None, but the function body unconditionally dereferences request.axes_attempt_time, causing an AttributeError when called without a request or with a request that hasn't gone through the axes failure-tracking path.

Root Cause

Line 23 in axes/attempts.py directly accesses request.axes_attempt_time without checking if request is None first. The existing # type: ignore[union-attr] comment acknowledges this is unsafe, but the actual guard was missing.

Fix

Changed request.axes_attempt_time to getattr(request, "axes_attempt_time", None), which safely handles both:

1. request=None (the default case)
2. request exists but hasn't been through the axes failure handler (no axes_attempt_time attribute)

In both cases, attempt_time will be None, and the function correctly falls back to now() - cool_off.

Testing

from axes.attempts import get_cool_off_threshold

# Before fix: AttributeError
# After fix: returns now() - cool_off
datetime = get_cool_off_threshold()