Bump org.specs2:specs2-junit_2.13 from 4.20.2 to 4.20.6

Bumps [org.specs2:specs2-junit_2.13](https://github.com/etorreborre/specs2) from 4.20.2 to 4.20.6.
- [Release notes](https://github.com/etorreborre/specs2/releases)
- [Commits](https://github.com/etorreborre/specs2/commits)

---
updated-dependencies:
- dependency-name: org.specs2:specs2-junit_2.13
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

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

polyglot-scala/pom.xml

@@ -81,7 +81,7 @@
     <dependency>
       <groupId>org.specs2</groupId>
       <artifactId>specs2-junit_${scala.bin.version}</artifactId>
-      <version>4.20.2</version>
+      <version>4.20.6</version>
       <scope>test</scope>
     </dependency>
   </dependencies>