Add a new job in the CI, which notifies ArgoCD through a webhook that a new
docker image has been pushed to the Docker registry. Thus, ArgoCD can sync
and pull the latest image.
Thus, main will be automatically deployed to staging.
Github secrets are difficult to maintain in time because we do not have
a way to track them efficiently. So to avoid this issue, we prefer to use
sops encrypted files to manage our secrets.
