Bump mockito.version from 5.20.0 to 5.21.0

Bumps `mockito.version` from 5.20.0 to 5.21.0.

Updates `org.mockito:mockito-core` from 5.20.0 to 5.21.0
- [Release notes](https://github.com/mockito/mockito/releases)
- [Commits](mockito/mockito@v5.20.0...v5.21.0)

Updates `org.mockito:mockito-junit-jupiter` from 5.20.0 to 5.21.0
- [Release notes](https://github.com/mockito/mockito/releases)
- [Commits](mockito/mockito@v5.20.0...v5.21.0)

---
updated-dependencies:
- dependency-name: org.mockito:mockito-core
  dependency-version: 5.21.0
  dependency-type: direct:development
  update-type: version-update:semver-minor
- dependency-name: org.mockito:mockito-junit-jupiter
  dependency-version: 5.21.0
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

pom.xml

@@ -109,7 +109,7 @@
     <junit.version>6.0.1</junit.version>
     <log4j.version>2.25.2</log4j.version>
     <lombok.version>1.18.42</lombok.version>
-    <mockito.version>5.20.0</mockito.version>
+    <mockito.version>5.21.0</mockito.version>
     <nextbreakpoint.flink.client.version>1.1.4</nextbreakpoint.flink.client.version>
     <picocli.version>4.7.7</picocli.version>
     <postgres.version>42.7.8</postgres.version>