pythonGH-65961: Document the deprecation of __package__ and __cached__

Author: brettcannon

Doc/library/importlib.rst

@@ -1237,8 +1237,8 @@ find and load modules.
    .. attribute:: has_location
 
    ``True`` if the spec's :attr:`origin` refers to a loadable location,
-    ``False`` otherwise.  This value impacts how :attr:`origin` is interpreted
-    and how the module's :attr:`__file__` is populated.
+   ``False`` otherwise.  This value impacts how :attr:`origin` is interpreted
+   and how the module's :attr:`__file__` is populated.
 
 
 .. class:: AppleFrameworkLoader(name, path)

Doc/reference/import.rst

@@ -596,6 +596,10 @@ listed below.
       Raise :exc:`DeprecationWarning` instead of :exc:`ImportWarning`
       when falling back to ``__package__``.
 
+   .. deprecated-removed:: 3.13 3.15
+      ``__package__`` will cease to be set or taken into consideration
+      by the import system or standard library.
+
 
 .. attribute:: __spec__
 
@@ -653,6 +657,10 @@ listed below.
    It is **strongly** recommended that you rely on :attr:`__spec__`
    instead of ``__cached__``.
 
+   .. deprecated-removed:: 3.13 3.15
+      ``__package__`` will cease to be set or taken into consideration
+      by the import system or standard library.
+
 .. _package-path-rules:
 
 module.__path__

Misc/NEWS.d/next/Core_and_Builtins/2024-09-23-13-25-27.gh-issue-65961.LDqXV2.rst

@@ -0,0 +1 @@
+Deprecate the setting and using ``__package__`` and ``__cached__``.