Add missing distribution attribute to distutils.cmd.Command (#9893)

Signed-off-by: Henry Schreiner <henryschreineriii@gmail.com>

stdlib/distutils/cmd.pyi

@@ -5,6 +5,7 @@ from distutils.dist import Distribution
 from typing import Any
 
 class Command:
+    distribution: Distribution
     sub_commands: list[tuple[str, Callable[[Command], bool] | None]]
     def __init__(self, dist: Distribution) -> None: ...
     @abstractmethod