add echo comment

.github/workflows/build.yml

@@ -52,6 +52,7 @@ jobs:
         run: poetry add git+https://github.com/EIT-ALIVE/eitprocessing.git#${{ inputs.caller_branch }}
       - name: Run Tests in Container
         run: >
+          echo "action triggered by: ${{github.event_name}}";
           docker run
           --rm
           -v $GITHUB_WORKSPACE:/ci