Make JacksonFeatureSet java.io.Serializable

Author: cowtowncoder

release-notes/VERSION-2.x

@@ -17,6 +17,7 @@ a pure JSON library.
 Not yet released:
 
 #1136: Change parsing error message to mention `-INF`
+- Make `JacksonFeatureSet` serializable
 
 2.16.0-rc1 (20-Oct-2023)
 

src/main/java/com/fasterxml/jackson/core/util/JacksonFeatureSet.java

@@ -9,7 +9,10 @@
  * @since 2.12
  */
 public final class JacksonFeatureSet<F extends JacksonFeature>
+    implements java.io.Serializable // since 2.16
 {
+    private static final long serialVersionUID = 1L;
+
     protected int _enabled;
 
     /**