CI: Link with ffmpeg for AppImage

[stenzek]

Description of Changes

Should cause linuxdeploy to pull in ffmpeg.

Rationale behind Changes

Increase distribution compatibility.
Size will increase, but the appimage is already huge, so whatever. Packaging on Linux just sucks to begin with.

Suggested Testing Steps

Test video capture with AppImage.

[RedDevilus]

Should ffmpeg also best be updated to 6.1.1? https://ffmpeg.org/download.html

[stenzek]

No, because it's using (and pulling in) the system libraries.

[stenzek]

48MB -> 94MB.... not worth it for a feature that barely anyone uses, IMO.

If you want video capture, I'd say just use the flatpak...

[TheTechnician27]

Made a 7-minute video and found no defect in it. Downloaded the AppImage and used on Manjaro.

[AmyRoxwell]

Works On EndeavourOS (Arch Linux), Also, HEVC and other encoders on AMD gpus work on mesa drivers! (nvm, double checked with a couple of games and it's using the cpu for the encoding not matter what encoder you choose....)

[AmyRoxwell]

Well, we have one problem, it doesn't utilize the gpu, it does all of it using the CPU, even if you have VAAPI, HEVC and other packages that should make it work on the gpu (lots of them included on the Mesa drivers + they utilize the gpu on stuff like obs), is there maybe some arguments that need to be put on the video encoder to make it utilize the gpu?

[stenzek]

Meh. Gonna draft it I think. Distributing software on Linux just sucks.

The best move would probably be to build our own ffmpeg with the required modules enabled. But that also means building libx264 etc, and I really can't be arsed.