C++: Fix change note.

Author: MathiasVP

cpp/ql/lib/change-notes/2023-03-16-use-use-flow.md

@@ -5,4 +5,7 @@ category: majorAnalysis
   The new library behaves much more like the dataflow library of other CodeQL supported
   languages by following use-use dataflow paths instead of def-use dataflow paths.
   The new library also better supports dataflow through indirections, and new predicates
-  such as `Node::asIndirectExpr` have been added to facilitate working with indirections.
+  such as `Node::asIndirectExpr` have been added to facilitate working with indirections.
+
+  The `semmle.code.cpp.ir.dataflow.DataFlow` library is now identical to the new
+  `semmle.code.cpp.dataflow.new.DataFlow` library.