Make ToEmptyObjectSerializer constructor public

Author: cowtowncoder

src/main/java/com/fasterxml/jackson/databind/ser/std/ToEmptyObjectSerializer.java

@@ -27,7 +27,8 @@
 public class ToEmptyObjectSerializer
     extends StdSerializer<Object>
 {
-    protected ToEmptyObjectSerializer(Class<?> raw) {
+    // `public` since 2.19
+    public ToEmptyObjectSerializer(Class<?> raw) {
         super(raw, false);
     }