Bump junit:junit from 4.12 to 4.13.1 in /firewall-app

Bumps [junit: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)

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

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

firewall-app/pom.xml

@@ -63,7 +63,7 @@
         <dependency>
             <groupId>junit</groupId>
             <artifactId>junit</artifactId>
-            <version>4.12</version>
+            <version>4.13.1</version>
             <scope>test</scope>
         </dependency>