* fix(flatpak): remove unused net.unstoppableswap.gui.json
This is the same as o.e.a.json just with a different id,
is unused, and was clearly supposed to be a rename,
not a copy, in the referenced commit
Fixes: 517a4fa574
* refactor(CI): clean up build-gui-release-binaries.yml
* refactor(publish_flatpak): deslopify. NFC
* refactor(publish_flatpak): lift out .flatpakrepo & .flatpakref
Common bits at the top for convenience
* feat(CI): build + upload flatpak to gh-pages in build-gui-release-binaries.yml
This is equivalent to the current flatpak releases except it also has
the icon
