Enhancement: Following the release cycle of gnome instead of ubuntu lts

[soumyaDghosh]

Current Scenario

The current gnome-sdk follows the release cycle of Ubuntu LTS, which means new content snap with each Ubuntu release. But, for that, often backward compatibility is lost. With each new gnome release, many libraries, functions, classes are deprecated, and only because libraries are mostly backward compatible, old apps, still can be used.

Improvements that can be done

Instead of following Ubuntu releases, if we can use tracks for each gnome release, and allow to mention the version of gnome in the extensions part, which then will do its job from snapcraft can be a better option. This work will also allow to be duplicated with libraries and UI toolkits that aren't backward compatible, like gstreamer, pipewire, ffmpeg and UI toolkits like qt and kde-framework.