Update ion-java to 1.11.9

Author: cowtowncoder

ion/pom.xml

@@ -39,7 +39,7 @@ tree model)
     <dependency>
       <groupId>com.amazon.ion</groupId>
       <artifactId>ion-java</artifactId>
-      <version>1.11.8</version>
+      <version>1.11.9</version>
     </dependency>
 
     <!-- Extends Jackson core, databind -->

release-notes/VERSION-2.x

@@ -20,8 +20,9 @@ Active maintainers:
 
 2.17.3 (not yet released)
 
-#506: Cannot deserialize `UUID` values
+#506: (protobuf) Cannot deserialize `UUID` values
  (reported by @uniquonil)
+- (ion) Upgrade `ion-java` to 1.11.9 (from 1.11.8)
 
 2.17.2 (05-Jul-2024)