Move Jackson version to property for consistency

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: jdereg

pom.xml

@@ -36,6 +36,7 @@
         <version.agrona>1.22.0</version.agrona> <!-- do not increase past 1.22.0 until abandoning JDK 8 support, class file format 52 -->
         <version.commons-collections4>4.5.0</version.commons-collections4>
         <version.guava>33.5.0-jre</version.guava>
+        <version.jackson-databind>2.21.1</version.jackson-databind>
 
         <!-- Build maven-***-plugins -->
         <version.maven-jar-plugin>3.5.0</version.maven-jar-plugin>
@@ -390,19 +391,12 @@
             <scope>test</scope>
         </dependency>
 
-        <!-- pom.xml snippets -->
         <dependency>
             <groupId>com.fasterxml.jackson.core</groupId>
             <artifactId>jackson-databind</artifactId>
-            <version>2.21.1</version>
+            <version>${version.jackson-databind}</version>
             <scope>test</scope>
         </dependency>
-        <dependency>
-            <groupId>com.fasterxml.jackson.dataformat</groupId>
-            <artifactId>jackson-dataformat-xml</artifactId>
-            <version>2.21.1</version>
-            <scope>test</scope>
-        </dependency>
-        
+
     </dependencies>
 </project>