Remove support for python <3.11 (#1273)

Python 3.11 ships with latest Debian Bookworm. 
pypy is not that widely used with this library based on statistics. It could be added back when pypy supports python 3.11.

tests/test_device.py

@@ -6,11 +6,11 @@ import importlib
 import inspect
 import pkgutil
 import sys
+import zoneinfo
 from contextlib import AbstractContextManager, nullcontext
 from unittest.mock import AsyncMock, patch
 
 import pytest
-import zoneinfo
 
 import kasa
 from kasa import Credentials, Device, DeviceConfig, DeviceType, KasaException, Module