Draft: Run Luigi task directly from Python instead of subprocess

.gitlab-ci.yml

@@ -15,6 +15,7 @@ variables:
         - export PATH=$PWD/.poetry/bin:$PATH
         - poetry config virtualenvs.in-project true
         - poetry install
+        - poetry add git+https://gitlab.cern.ch/lhcb-core/nightly-builds/lb-nightly-scheduler.git
         - poetry run celery -A lb.nightly.rpc worker -l DEBUG -O fair -n checkout@%h --pidfile=/tmp/%n.pid --logfile=/tmp/%p%I.log &
         - poetry run celery -A lb.nightly.rpc worker -l DEBUG -O fair -c 1 -n build@%h --pidfile=/tmp/%n.pid --logfile=/tmp/%p%I.log &
         - poetry run celery -A lb.nightly.rpc worker -l DEBUG -O fair -n test@%h --pidfile=/tmp/%n.pid --logfile=/tmp/%p%I.log &