Import from collections.abc wherever possible (#7635)

stdlib/mailbox.pyi

@@ -2,8 +2,9 @@ import email.message
 import sys
 from _typeshed import Self, StrOrBytesPath
 from abc import ABCMeta, abstractmethod
+from collections.abc import Callable, Iterable, Iterator, Mapping, Sequence
 from types import TracebackType
-from typing import IO, Any, AnyStr, Callable, Generic, Iterable, Iterator, Mapping, Protocol, Sequence, TypeVar, overload
+from typing import IO, Any, AnyStr, Generic, Protocol, TypeVar, overload
 from typing_extensions import Literal, TypeAlias
 
 if sys.version_info >= (3, 9):