Bump com.fasterxml.jackson:jackson-bom in /lang/java (#3633)

Bumps [com.fasterxml.jackson:jackson-bom](https://github.com/FasterXML/jackson-bom) from 2.20.1 to 2.21.0.
- [Commits](FasterXML/jackson-bom@jackson-bom-2.20.1...jackson-bom-2.21.0)

---
updated-dependencies:
- dependency-name: com.fasterxml.jackson:jackson-bom
  dependency-version: 2.21.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

lang/java/pom.xml

@@ -45,7 +45,7 @@
     <grpc.version>1.78.0</grpc.version>
     <hadoop.version>3.4.2</hadoop.version>
     <hamcrest.version>3.0</hamcrest.version>
-    <jackson-bom.version>2.20.1</jackson-bom.version>
+    <jackson-bom.version>2.21.0</jackson-bom.version>
     <jetty.version>9.4.58.v20250814</jetty.version>
     <jopt-simple.version>5.0.4</jopt-simple.version>
     <junit5.version>5.14.2</junit5.version>