Update Doc/whatsnew/3.15.rst

Co-authored-by: Mikhail Efimov <[email protected]>

Author: sergey-miryanov

Doc/whatsnew/3.15.rst

@@ -806,8 +806,8 @@ New features
 Changed C APIs
 --------------
 
-* 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` must be set too.
+* If the :c:macro:`Py_TPFLAGS_MANAGED_DICT` or :c:macro:`Py_TPFLAGS_MANAGED_WEAKREF`
+  flag is set then :c:macro:`Py_TPFLAGS_HAVE_GC` must be set too.
   (Contributed by Sergey Miryanov in :gh:`134786`)