Don't remove from Pending removal

Author: encukou

Doc/deprecations/pending-removal-in-3.15.rst

@@ -1,6 +1,13 @@
 Pending removal in Python 3.15
 ------------------------------
 
+* The import system:
+
+  * Setting ``__cached__`` on a module while
+    failing to set :attr:`__spec__.cached <importlib.machinery.ModuleSpec.cached>`
+    is deprecated. In Python 3.15, ``__cached__`` will cease to be set or
+    take into consideration by the import system or standard library. (:gh:`97879`)
+
 * :mod:`ctypes`:
 
   * The undocumented :func:`!ctypes.SetPointerType` function