Update release notes wrt backport #445 fix

Author: cowtowncoder

release-notes/CREDITS-2.x

@@ -244,3 +244,9 @@ Peter Haumer (phaumer@github)
 
 * Reported #404: (yaml) Cannot serialize YAML with Deduction-Based Polymorphism
  (2.15.1)
+
+Arthur Chan (arthurscchan@github)
+
+* Contributed fix for #445: `YAMLParser` throws unexpected `NullPointerException` in certain
+  number parsing cases
+ (2.16.1)

release-notes/VERSION-2.x

@@ -14,6 +14,12 @@ Active Maintainers:
 === Releases ===
 ------------------------------------------------------------------------
 
+2.16.1 (not yet released)
+
+#445: `YAMLParser` throws unexpected `NullPointerException` in certain
+  number parsing cases
+ (fix contributed by Arthur C)
+
 2.16.0 (15-Nov-2023)
 
 #198: (csv) Support writing numbers as quoted Strings with