Publish to GitLab Package Registry

.github/workflows/publish.yml

@@ -17,6 +17,7 @@ jobs:
       - name: Publish with Gradle
         uses: gradle/gradle-build-action@v2
         with:
-          arguments: publishAllPublicationsToGitHubPackagesRepository
+          arguments: publishAllPublicationsToGitHubPackagesRepository publishAllPublicationsToGitLabRepository
         env:
           GITHUB_TOKEN: "${{ secrets.GITHUB_TOKEN }}"
+          GITLAB_TOKEN: "${{ secrets.GITLAB_TOKEN }}"