remove unneeded Iterable base class from CookieJar (#12812)

stdlib/http/cookiejar.pyi

@@ -1,6 +1,6 @@
 import sys
 from _typeshed import StrPath
-from collections.abc import Iterable, Iterator, Sequence
+from collections.abc import Iterator, Sequence
 from http.client import HTTPResponse
 from re import Pattern
 from typing import ClassVar, TypeVar, overload
@@ -21,7 +21,7 @@ _T = TypeVar("_T")
 
 class LoadError(OSError): ...
 
-class CookieJar(Iterable[Cookie]):
+class CookieJar:
     non_word_re: ClassVar[Pattern[str]]  # undocumented
     quote_re: ClassVar[Pattern[str]]  # undocumented
     strict_domain_re: ClassVar[Pattern[str]]  # undocumented