Update docs according review's feedback

Author: sergey-miryanov

Doc/c-api/typeobj.rst

@@ -1260,7 +1260,7 @@ and :c:data:`PyType_Type` effectively act as defaults.)
       This bit indicates that instances of the class have a :attr:`~object.__dict__`
       attribute, and that the space for the dictionary is managed by the VM.
 
-      If this flag is set, :c:macro:`Py_TPFLAGS_HAVE_GC` should also be set.
+      If this flag is set, :c:macro:`Py_TPFLAGS_HAVE_GC` must also be set.
 
       The type traverse function must call :c:func:`PyObject_VisitManagedDict`
       and its clear function must call :c:func:`PyObject_ClearManagedDict`.
@@ -1278,7 +1278,7 @@ and :c:data:`PyType_Type` effectively act as defaults.)
       This bit indicates that instances of the class should be weakly
       referenceable.
 
-      If this flag is set, :c:macro:`Py_TPFLAGS_HAVE_GC` should also be set.
+      If this flag is set, :c:macro:`Py_TPFLAGS_HAVE_GC` must also be set.
 
       .. versionadded:: 3.12
 

Doc/whatsnew/3.15.rst

@@ -785,13 +785,6 @@ New features
   (Contributed by Victor Stinner in :gh:`129813`.)
 
 
-Limited C API changes
----------------------
-
-* If the :c:macro:`Py_TPFLAGS_MANAGED_DICT` and :c:macro:`Py_TPFLAGS_MANAGED_WEAKREF`
-  flags are set then :c:macro:`Py_TPFLAGS_HAVE_GC` should be set too.
-  (Contributed by Sergey Miryanov in :gh:`134786`)
-
 
 Porting to Python 3.15
 ----------------------

Include/object.h

@@ -529,7 +529,7 @@ given type object has a specified feature.
 #define Py_TPFLAGS_INLINE_VALUES (1 << 2)
 
 /* Placement of weakref pointers are managed by the VM, not by the type.
- * The VM will automatically set tp_weaklistoffset. Implies Py_TPFLAGS_HAVE_GC.
+ * The VM will automatically set tp_weaklistoffset.
  */
 #define Py_TPFLAGS_MANAGED_WEAKREF (1 << 3)