[http.cookies] 'value', 'coded_value', and 'key' of Morsel can return None (#15264)

stdlib/http/cookies.pyi

@@ -1,3 +1,4 @@
+from _typeshed import MaybeNone
 from collections.abc import Iterable, Mapping
 from types import GenericAlias
 from typing import Any, Generic, TypeVar, overload
@@ -21,11 +22,11 @@ class CookieError(Exception): ...
 
 class Morsel(dict[str, Any], Generic[_T]):
     @property
-    def value(self) -> str: ...
+    def value(self) -> str | MaybeNone: ...
     @property
-    def coded_value(self) -> _T: ...
+    def coded_value(self) -> _T | MaybeNone: ...
     @property
-    def key(self) -> str: ...
+    def key(self) -> str | MaybeNone: ...
     def __init__(self) -> None: ...
     def set(self, key: str, val: str, coded_val: _T) -> None: ...
     def setdefault(self, key: str, val: str | None = None) -> str: ...