Trigger extension CI automatically after this CI finishes

.gitlab-ci.yml

@@ -17,3 +17,16 @@ test:
       - .gradle/caches
       - .gradle/native
       - .gradle/wrapper
+
+trigger_extension_build:
+  stage: .post
+  image: alpine:3
+  dependencies: []
+  variables:
+    GIT_STRATEGY: none
+  before_script:
+    - apk add --update curl
+  script:
+    - curl -X POST -F "token=$CI_JOB_TOKEN" -F "ref=main" https://gitlab.cs.uni-duesseldorf.de/api/v4/projects/2835/trigger/pipeline
+  only:
+    - master@general/stups/b_language_server