bpo-42927: Update the What's new entry for LOAD_ATTR optimizations (GH-24383)

Author: pablogsal

Doc/whatsnew/3.10.rst

@@ -556,10 +556,10 @@ Optimizations
   (Contributed by Victor Stinner in :issue:`41006`.)
 
 * The ``LOAD_ATTR`` instruction now uses new "per opcode cache" mechanism.  It
-  is about 36% faster now. This makes optimized ``LOAD_ATTR`` instructions the
-  current most performance attribute access method (faster than slots).
-  (Contributed by Pablo Galindo and Yury Selivanov in :issue:`42093`, based on
-  ideas implemented originally in PyPy and MicroPython.)
+  is about 36% faster now for regular attributes and 44% faster for slots.
+  (Contributed by Pablo Galindo and Yury Selivanov in :issue:`42093` and Guido
+  van Rossum in :issue:`42927`, based on ideas implemented originally in PyPy
+  and MicroPython.)
 
 * When building Python with ``--enable-optimizations`` now
   ``-fno-semantic-interposition`` is added to both the compile and link line.