Update release notes

Author: cowtowncoder

release-notes/CREDITS-2.x

@@ -381,3 +381,7 @@ Cormac Redmond (@credmond)
 Manuel Sugawara (@sugmanue)
  * Contributed #568: Improve ASCII decoding performance for `CBORParser`
   (2.19.0)
+
+Josh Curry (@seadbrane)
+ * Reported, contributed fix for #571: Unable to deserialize a pojo with IonStruct
+  (2.19.0)

release-notes/VERSION-2.x

@@ -14,6 +14,9 @@ Active maintainers:
 === Releases ===
 ------------------------------------------------------------------------
 
+#571: Unable to deserialize a pojo with IonStruct
+ (reported, fix contributed by Josh C)
+
 2.19.0-rc2 (07-Apr-2025)
 
 #300: (smile) Floats are encoded with sign extension while doubles without