[stdlib/enum] add enum.bin (#15388)

docs: https://docs.python.org/dev/library/enum.html#enum.bin
source: https://github.com/python/cpython/blob/3.11/Lib/enum.py#L132-L154

stdlib/enum.pyi

@@ -4,7 +4,7 @@ import types
 from _typeshed import SupportsKeysAndGetItem, Unused
 from builtins import property as _builtins_property
 from collections.abc import Callable, Iterable, Iterator, Mapping
-from typing import Any, Final, Generic, Literal, TypeVar, overload
+from typing import Any, Final, Generic, Literal, SupportsIndex, TypeVar, overload
 from typing_extensions import Self, TypeAlias, disjoint_base
 
 __all__ = ["EnumMeta", "Enum", "IntEnum", "Flag", "IntFlag", "auto", "unique"]
@@ -311,6 +311,7 @@ if sys.version_info >= (3, 11):
     def global_enum_repr(self: Enum) -> str: ...
     def global_flag_repr(self: Flag) -> str: ...
     def show_flag_values(value: int) -> list[int]: ...
+    def bin(num: SupportsIndex, max_bits: int | None = None) -> str: ...
 
 if sys.version_info >= (3, 12):
     # The body of the class is the same, but the base classes are different.