flatpak: Bump the SDK to master

This is needed for the latest version of libhandy to work.

Trying to build a Calls flatpak with this patch, I get the following:

$ flatpak-builder --force-clean ../calls-flatpak-build sm.puri.Calls.json
error: org.gnome.Sdk/x86_64/master not installed
Failed to init: Unable to find sdk org.gnome.Sdk version master
$ flatpak remote-info flathub org.gnome.Sdk//master
error: Error searching remote flathub: Can't find ref org.gnome.Sdk//master

This doesn't seem to work.

According to https://www.ostechnix.com/flatpak-new-framework-desktop-applications-linux/ the version "master" is available from the gnome-nightly-apps repository. I followed the instructions in our developer documentation which makes no mention of gnome-nightly-apps. I think the developer documentation needs to be updated first to include this other repository.

I totally agree (and in fact tought @adrien.plazas updated the docs about that a while ago). Maybe @david.boddie can step in?

OK, so libhandy depends on the SDK version only available in the gnome-nightly-apps repository? I guess we'll need to add the other repository to the instructions, then. I'm guessing that this will change at some point after a new SDK release, though maybe just relying on "master" is good enough.

mentioned in issue developer.puri.sm#59 (closed)

merged

mentioned in commit 758573f1