ci: Start using GNOME Release Service
See https://handbook.gnome.org/maintainers/making-a-release.html
- Here's a successful test pipeline that ran on my personal fork https://gitlab.gnome.org/felipeborges/gnome-connections/-/pipelines/777927
- Here's the tarball uploaded to the test sandbox server https://gnome-release-route-sandbox-fileserver-gnome-release-service.apps.openshift.gnome.org/gnome-connections/48/
This MR needs to be backported to gnome-46 and gnome-47 stable branches for their upcoming releases.