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
...

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