khal is now unusable, at least when trying to add events:
```
Traceback (most recent call last):
File "/usr/bin/khal", line 5, in <module>
main_khal()
File "/usr/lib/python3/dist-packages/click/core.py", line 1157, in __call__
return self.main(*args, **kwargs)
^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/lib/python3/dist-packages/click/core.py", line 1078, in main
rv = self.invoke(ctx)
^^^^^^^^^^^^^^^^
File "/usr/lib/python3/dist-packages/click/core.py", line 1688, in invoke
return _process_result(sub_ctx.command.invoke(sub_ctx))
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/lib/python3/dist-packages/click/core.py", line 1434, in invoke
return ctx.invoke(self.callback, **ctx.params)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/lib/python3/dist-packages/click/core.py", line 783, in invoke
return __callback(*args, **kwargs)
^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/lib/python3/dist-packages/click/decorators.py", line 33, in new_func
return f(get_current_context(), *args, **kwargs)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/lib/python3/dist-packages/khal/cli.py", line 393, in new
new_func(
File "/usr/lib/python3/dist-packages/khal/controllers.py", line 399, in new_from_string
new_from_dict(info, collection, conf=conf, format=format, env=env, calendar_name=calendar_name)
File "/usr/lib/python3/dist-packages/khal/controllers.py", line 423, in new_from_dict
collection.insert(event)
File "/usr/lib/python3/dist-packages/khal/khalendar/khalendar.py", line 224, in insert
event.href, event.etag = self._storages[calendar].upload(event)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/lib/python3/dist-packages/khal/khalendar/vdir.py", line 210, in upload
if not isinstance(item.raw, str):
^^^^^^^^
File "/usr/lib/python3/dist-packages/khal/khalendar/event.py", line 385, in raw
timezone = create_timezone(tzinfo, self.start)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/lib/python3/dist-packages/khal/khalendar/event.py", line 903, in create_timezone
for one, two in iter(tz._tzinfos.items()) # type: ignore
^^^^^^^^^^^
AttributeError: 'zoneinfo.ZoneInfo' object has no attribute '_tzinfos'
```