Restore PDF rendering that got removed somehow

We need at least one build to properly test it so that it doesn't fail
at release time.

It used to be tested but somehow someone removed it.

.github/workflows/ci-actions.yml

@@ -82,7 +82,7 @@ jobs:
           restore-only: ${{ github.event_name == 'pull_request' }}
       - name: Build
         run: |
-          mvn -e -B  -DskipTests=true -Dno-format -DskipDocs clean install
+          mvn -e -B -DskipTests -DskipITs -Dno-format -Ddocumentation-pdf clean install
       - name: Tar Maven Repo
         shell: bash
         run: tar -czvf maven-repo.tgz -C ~ .m2/repository