chore: added entries to NEWS and UPGRADING

Author: NickSdot

NEWS

@@ -53,6 +53,7 @@ PHP                                                                        NEWS
     evaluation) and GH-18464 (Recursion protection for deprecation constants not
     released on bailout). (DanielEScherzer and ilutov)
   . Fixed AST printing for immediately invoked Closure. (Dmitrii Derepko)
+  . Property hooks are now allowed on backed readonly properties. ()
 
 - Curl:
   . Added curl_multi_get_handles(). (timwolla)

UPGRADING

@@ -144,6 +144,8 @@ PHP 8.5 UPGRADE NOTES
     RFC: https://wiki.php.net/rfc/attributes-on-constants
   . The #[\Deprecated] attribute can now be used on constants.
     RFC: https://wiki.php.net/rfc/attributes-on-constants
+  . Property hooks are now allowed on backed readonly properties.
+    RFC: https://wiki.php.net/rfc/readonly_hooks
 
 - Curl:
   . Added support for share handles that are persisted across multiple PHP