Update to flatpak-flutter tool

[JanKoudijs]

Follow up from: https://github.com/kra-mo/Sly/issues/16#issuecomment-2613939479

This Flatpak manifest update provides a Flutter source build of Sly, bringing in aarch64 support.
The Flutter version used is 3.27.3, this can be changed if Sly is using a different version.
I targeted the beta branch, but also this can change if needed.

If Sly dependencies change the sources and modules files can be regenerated by using the flatpak-flutter tool.

As a test Sly was built on a Raspberry Pi 4, here is a screenshot of it running:

[flathubbot]

Started test build 179407

[flathubbot]

Build 179407 successful
To test this build, install it from the testing repository:

flatpak install --user https://dl.flathub.org/build-repo/162568/page.kramo.Sly.flatpakref

[faveoled]

bot, build

[flathubbot]

Queued test build for page.kramo.Sly.

[kra-mo]

Hi, sorry, I'm a bit busy, but I'll review this in time.

[kra-mo]

Thanks, can you please make all of the manifests JSON instead of YAML?

[JanKoudijs]

can you please make all of the manifests JSON instead of YAML?

Not at this moment. I'm currently working on an update of the flatpak-flutter tool, where I move to a single top-level manifest, from which the offline manifest will be generated (less maintenance). First version of this generator will only support yaml. If we now convert the current yaml files to json it will make the migration to the new version harder. TheAppgineer/flatpak-flutter#4

Be aware that all the json files, containing the modules and sources, are generated and don't need maintenance.

[kra-mo]

Okay. Thanks for your work and it would be nice to support ARM, but then for the time being, I think I'll wait until there is an option for a JSON manifest.

Some tooling (eg. GNOME Builder) cannot work with YAML manifests and I myself can't test it with the scripts I have without rewriting them and introducing dependencies. (I do wish working with YAML was easier but at this point, I hope you understand.)

[JanKoudijs]

No problem. I created an issue for your request.

If you prefer to close this PR, feel free to do so.

[kra-mo]

I'd prefer to leave it open, but it would be nice if you marked it as a draft. Thank you.

[JanKoudijs]

can you please make all of the manifests JSON instead of YAML?

Currently Sly has a yaml manifest, does this mean that from now on your plan is to maintain a json manifest?

[kra-mo]

Yeah, the current manifest was mostly copied from LocalSend iirc and I just tested the binaries directly from CI. But here, that is a little more difficult so it would be nice if I could actually test the Flatpak.

[flathubbot]

Started test build 184590

[flathubbot]

Build 184590 successful
To test this build, install it from the testing repository:

flatpak install --user https://dl.flathub.org/build-repo/167819/page.kramo.Sly.flatpakref

[JanKoudijs]

Adding support for a .json manifest turned out to be pretty straightforward, so here you have it :)

Before making the final transition, I suggest you go through the README and try the build yourself.

[kra-mo]

Sorry for still not responding, it is definitely on my to do, but I'm busy with a lot of stuff right now.

[kra-mo]

I get the error that setup-flutter.sh is not found when trying to build the Flatpak.

[kra-mo]

Although that only happens in GNOME Builder so probably not an issue with the PR :p

[kra-mo]

Thank you.