Bump junit from 4.12 to 4.13.1 in /clients

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](junit-team/junit4@r4.12...r4.13.1)

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

Author: dependabot[bot]

clients/pom.xml

@@ -70,7 +70,7 @@
     <joda.version>2.7</joda.version>
     <jmh.version>1.19</jmh.version>
     <jmock.version>2.8.2</jmock.version>
-    <junit.version>4.12</junit.version>
+    <junit.version>4.13.1</junit.version>
     <lombok.version>1.16.22</lombok.version>
     <mockito.version>2.22.0</mockito.version>
     <netty.version>4.1.48.Final</netty.version>