Draft: Change ReduceMean attribute 'axes' from static array to dynamic vector

.gitlab/ci/build.gitlab-ci.yml

@@ -11,6 +11,7 @@ build:ubuntu_cpp:
     # aidge_core
     - DEPENDENCY_NAME="aidge_core"
     - DEPENDENCY_JOB="build:ubuntu_cpp"
+    - echo $CI_OPEN_MERGE_REQUEST
     - !reference [.download_dependency, script]
 
     # Build current module