Migrate config_entries to use propcache cached_property

missed this one, found by #127482

homeassistant/config_entries.py

@@ -18,13 +18,14 @@
 from datetime import datetime
 from enum import Enum, StrEnum
 import functools
-from functools import cache, cached_property
+from functools import cache
 import logging
 from random import randint
 from types import MappingProxyType
 from typing import TYPE_CHECKING, Any, Generic, Self, cast
 
 from async_interrupt import interrupt
+from propcache import cached_property
 from typing_extensions import TypeVar
 
 from . import data_entry_flow, loader