unshallow git history for sonar scanning

.gitlab-ci.yml

@@ -30,6 +30,8 @@ sonar:
     - gradle-node
   allow_failure: true
   dependencies: []
+  variables:
+    GIT_DEPTH: "0"
   script:
     - gradle sonarqube -Dsonar.host.url=https://scm.thm.de/sonar/