chore: enable Jupyter Notebook gateway for the Dataproc cluster (#651)

Sometimes it is very useful to be able to spin up a Jupyter notebook on a Dataproc cluster which has access to Gentropy and all its configured environment. Previously, I already added the “enable_component_gateway” option; however, it doesn't really take any effect unless you also specify the list of components to enable, which is what I'm doing in this PR.

src/airflow/dags/common_airflow.py

@@ -112,6 +112,7 @@ def create_cluster(
         num_workers=num_workers,
         image_version=GCP_DATAPROC_IMAGE,
         enable_component_gateway=True,
+        optional_components=["JUPYTER"],
         init_actions_uris=INITIALISATION_EXECUTABLE_FILE,
         metadata={
             "CONFIGTAR": CONFIG_TAG,