build(deps-dev): bump junit from 4.11 to 4.13.1 in /playground/java (#39)

Bumps [junit](https://github.com/junit-team/junit4) from 4.11 to 4.13.1.
- [Release notes](https://github.com/junit-team/junit4/releases)
- [Changelog](https://github.com/junit-team/junit4/blob/main/doc/ReleaseNotes4.11.md)
- [Commits](junit-team/junit4@r4.11...r4.13.1)

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

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

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

Author: dependabot[bot]

playground/java/pom.xml

@@ -20,7 +20,7 @@
     <dependency>
       <groupId>junit</groupId>
       <artifactId>junit</artifactId>
-      <version>4.11</version>
+      <version>4.13.1</version>
       <scope>test</scope>
     </dependency>
     <dependency>