Bump junit from 4.11 to 4.13.1 in /nopol-server (SpoonLabs#205)

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)

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

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

Author: dependabot[bot]

nopol-server/pom.xml

@@ -53,7 +53,7 @@
         <dependency>
             <groupId>junit</groupId>
             <artifactId>junit</artifactId>
-            <version>4.11</version>
+            <version>4.13.1</version>
         </dependency>
 
         <dependency>