WIP: data: Remove GNOME branding

This MR is part of an [initiative](GNOME/Initiatives#35) to fade out legacy app branding. Following the [Software Policy](https://wiki.gnome.org/Foundation/SoftwarePolicy), GNOME branding is reserved for official GNOME software (Core apps and Development tools.) You can find a summary in [this blog post](https://blogs.gnome.org/sophieh/2022/06/08/apps-attempt-of-a-status-report/).

If you think that your app is a special case that needs an exception from the software policy, we would ask you to leave a comment about your app's case in GNOME/Initiatives#35.

/label ~"9. Initiative: Legacy app branding"
2 jobs for rebranding in 6 minutes and 40 seconds (queued for 48 seconds)