ICU-22193 Bump junit from 4.12 to 4.13.1 in /icu4j/maven-build

ICU-22193 Bump junit from 4.12 to 4.13.1 in /icu4j/maven-build

Bumps [junit](https://github.com/junit-team/junit4) from 4.12 to 4.13.1.
- [Release notes](https://github.com/junit-team/junit4/releases)
- [Changelog](https://github.com/junit-team/junit4/blob/main/doc/ReleaseNotes4.12.md)
- [Commits](https://github.com/junit-team/junit4/compare/r4.12...r4.13.1)

---
updated-dependencies:
- dependency-name: junit:junit
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>