ORC-2135: Upgrade mockito to 5.23.0

### What changes were proposed in this pull request?

This PR upgrades `mockito` to 5.23.0 to bring Java 25 related bug fix.

### Why are the changes needed?

To keep the test dependency up to date with the latest bug fixes.
- https://github.com/mockito/mockito/releases/tag/v5.23.0
- https://github.com/mockito/mockito/releases/tag/v5.22.0
  - mockito/mockito#3778
  - mockito/mockito#3785

### How was this patch tested?

Pass the CIs with the existing tests.

### Was this patch authored or co-authored using generative AI tooling?

Generated-by: Claude Code (claude-opus-4-6)

Closes #2585 from dongjoon-hyun/ORC-2135.

Authored-by: Dongjoon Hyun <dongjoon@apache.org>
Signed-off-by: Dongjoon Hyun <dongjoon@apache.org>
(cherry picked from commit 25d32b7)
Signed-off-by: Dongjoon Hyun <dongjoon@apache.org>

Author: dongjoon-hyun

java/pom.xml

@@ -84,7 +84,7 @@
     <maven.compiler.useIncrementalCompilation>false</maven.compiler.useIncrementalCompilation>
     <maven.version>3.9.13</maven.version>
 
-    <mockito.version>5.21.0</mockito.version>
+    <mockito.version>5.23.0</mockito.version>
     <orc-format.version>1.1.1</orc-format.version>
     <!-- Build Properties -->
     <project.build.outputTimestamp>2026-02-25T11:39:48Z</project.build.outputTimestamp>