Ubuntu and its flavours to remove FlatPak support

As part of our combined efforts, the Ubuntu flavors have made a joint decision to adjust some of the default packages on Ubuntu: Going forward, the Flatpak package as well as the packages to integrate Flatpak into the respective software center will no longer be installed by default in the next release due in April 2023, Lunar Lobster. Users who have used Flatpak will not be affected on upgrade, as flavors are including a special migration that takes this into account. Those who haven't interacted with Flatpak will be presented with software from the Ubuntu repositories and the Snap Store.

We think this will improve the out-of-the-box Ubuntu experience for new users while respecting how existing users personalize their own experiences. However, we don't want this to come as a surprise. If you have comments specific to this change you are welcome to respond here on discourse.

Canonical's got Snap to peddle, so FlatPak is a competitor. That's all there's to it. I maintain they're all bad and unnecessary - a .deb, an .rpm, and your source code is all you need to cover 99.9% of Linux users in a standard, easy-to-use, uncompromising way.