Avoid offset error in taskwarrior DST calculation

taskwarrior seems to have a problem with time zones with daylight saving
time when doing calculations:

$ TZ=UTC task calc "eoy - 4 months"
2022-09-02T23:59:59
$ TZ=Europe/Berlin task calc "eoy - 4 months"
2022-09-03T00:59:59

The old pytz code did the same and computed 2022-09-03T00:59:59 whereas
the new zoneinfo version computes 2022-09-02T23:59:59. Instead of
working around taskwarrior this changes the test to be outside of the
DST.

Author: jspricke

tasklib/tests.py

@@ -1267,7 +1267,7 @@ def test_complex_eoy_conversion(self):
             else:
                 return
 
-        t = Task(self.tw, description='test task', due='eoy - 4 months')
+        t = Task(self.tw, description='test task', due='eoy - 2 months')
         now = datetime.datetime.now().replace(tzinfo=local_zone)
         due_date = datetime.datetime(
             year=now.year,
@@ -1277,7 +1277,7 @@ def test_complex_eoy_conversion(self):
             minute=59,
             second=59,
             tzinfo=local_zone
-        ) - datetime.timedelta(0, 4 * 30 * 86400)
+        ) - datetime.timedelta(0, 2 * 30 * 86400)
         if self.tw.version >= '2.5.2' and self.tw.version < '2.6.0':
             due_date = datetime.datetime(
                 year=now.year+1,
@@ -1287,7 +1287,7 @@ def test_complex_eoy_conversion(self):
                 minute=0,
                 second=0,
                 tzinfo=local_zone
-            ) - datetime.timedelta(0, 4 * 30 * 86400)
+            ) - datetime.timedelta(0, 2 * 30 * 86400)
         self.assertEqual(due_date, t['due'])
 
     def test_filtering_with_string_datetime(self):