Use cached_property from the stdlib

Our local implementation preceded the one in the stdlib, but we no
longer support versions of Python which do not ship it.

vdirsyncer/cli/config.py

@@ -4,6 +4,7 @@ import json
 import os
 import string
 from configparser import RawConfigParser
+from functools import cached_property
 from itertools import chain
 from typing import IO
 from typing import Any
@@ -11,7 +12,6 @@ from typing import Generator
 
 from vdirsyncer import PROJECT_HOME
 from vdirsyncer import exceptions
-from vdirsyncer.utils import cached_property
 from vdirsyncer.utils import expand_path
 from vdirsyncer.vobject import Item
 

vdirsyncer/storage/dav.py

@@ -6,6 +6,7 @@ import logging
 import urllib.parse as urlparse
 import xml.etree.ElementTree as etree
 from abc import abstractmethod
+from functools import cached_property
 from inspect import getfullargspec
 from inspect import signature
 
@@ -390,7 +391,7 @@ class DAVSession:
         self.url = url.rstrip("/") + "/"
         self.connector = connector
 
-    @utils.cached_property
+    @cached_property
     def parsed_url(self):
         return urlparse.urlparse(self.url)
 

vdirsyncer/utils.py

@@ -145,24 +145,6 @@ def checkfile(path, create=False) -> None:
             raise exceptions.CollectionNotFound(f"File {path} does not exist.")
 
 
-class cached_property:
-    """A read-only @property that is only evaluated once. Only usable on class
-    instances' methods.
-    """
-
-    def __init__(self, fget, doc=None):
-        self.__name__ = fget.__name__
-        self.__module__ = fget.__module__
-        self.__doc__ = doc or fget.__doc__
-        self.fget = fget
-
-    def __get__(self, obj, cls):
-        if obj is None:  # pragma: no cover
-            return self
-        obj.__dict__[self.__name__] = result = self.fget(obj)
-        return result
-
-
 def href_safe(ident, safe=SAFE_UID_CHARS):
     return not bool(set(ident) - set(safe))
 

vdirsyncer/vobject.py

@@ -1,10 +1,10 @@
 from __future__ import annotations
 
 import hashlib
+from functools import cached_property
 from itertools import chain
 from itertools import tee
 
-from .utils import cached_property
 from .utils import uniq
 
 IGNORE_PROPS = (