Use correct maven goal

.gitlab-ci.yml

@@ -8,7 +8,7 @@ pages:
   image: maven:3.8.4-eclipse-temurin-17-alpine
   script:
     - mvn --version
-    - mvn clean install   # build p2 repo
+    - mvn p2:site   # build p2 repo
     - rm -rf $RELEASE_DIR
     - mkdir -p $RELEASE_DIR
     - cp -r de.hft-stuttgart.indriya.p2site/target/repository/* $RELEASE_DIR