bpo-41282: Add deprecation warning and docs for distutils (PEP 632)

[zooba]

https://bugs.python.org/issue41282

[methane]

I see this warning is emit for distutils/__init__.py.

/Users/inada-n/work/python/cpython/Lib/distutils/__init__.py:16: DeprecationWarning: The distutils package is deprecated and slated for removal in Python 3.12. Use setuptools or check PEP 632 for potential alternatives

How about adding stacklevel to emit warning for modules importing distutils?

patch:

--- a/Lib/distutils/__init__.py
+++ b/Lib/distutils/__init__.py
@@ -16,4 +16,4 @@
 warnings.warn("The distutils package is deprecated and slated for "
               "removal in Python 3.12. Use setuptools or check "
               "PEP 632 for potential alternatives",
-              DeprecationWarning)
+              DeprecationWarning, 2)

warning:

/Users/inada-n/work/python/cpython/./setup.py:33: DeprecationWarning: The distutils package is deprecated and slated for removal in Python 3.12. Use setuptools or check PEP 632 for potential alternatives

PR: #24657