Fix import of backports.zoneinfo

Author: jspricke

tasklib/serializing.py

@@ -1,7 +1,10 @@
 import datetime
 import importlib
 import json
-from zoneinfo import ZoneInfo
+try:
+    from zoneinfo import ZoneInfo
+except ImportError:
+    from backports.zoneinfo import ZoneInfo
 
 
 from .lazy import LazyUUIDTaskSet, LazyUUIDTask

tasklib/tests.py

@@ -10,7 +10,10 @@
 import tempfile
 import unittest
 from io import StringIO
-from zoneinfo import ZoneInfo
+try:
+    from zoneinfo import ZoneInfo
+except ImportError:
+    from backports.zoneinfo import ZoneInfo
 
 from .backends import TaskWarrior
 from .task import Task, ReadOnlyDictView