Change AppImage packaging to actively maintained system

[hcorion]

The previous system is basically unmaintained, this new AppImage packager has proper support for Qt6, and active support from the AppImage team.
In addition, I'm removing a bunch of our old lib hacks and the old ugly C++ library check system.

[MastaG]

I dont know if it's already the case, but could you make sure the included Qt libraries ship with Wayland platform enabled as well?
We're in 2023 now and most Linux distributions ship with a Wayland enabled desktop environment by default.
So some regression testing on Wayland would be nice.

[AniLeo]

Most of the team members that use Linux use X if I'm not mistaken, myself included, that's why regressions on Wayland sometimes go unnoticed

[13xforever]

Unfortunately I've upgraded to Fedora 38 already, where they switched to qt6, so lots of qt5 apps have issues, including rpcs3 where it refuses to run at all now.

[l3xforever@ls-fedora Downloads]$ ./rpcs3.AppImage 
Debugger: 0
Warning: Ignoring XDG_SESSION_TYPE=wayland on Gnome. Use QT_QPA_PLATFORM=wayland to run on Wayland anyway.
: CommandLine Error: Option 'use-dbg-addr' registered more than once!
LLVM ERROR: inconsistency in registered CommandLine options
Aborted (core dumped)
[l3xforever@ls-fedora Downloads]$ QT_QPA_PLATFORM=wayland ./rpcs3.AppImage 
Debugger: 0
Warning: Ignoring XDG_SESSION_TYPE=wayland on Gnome. Use QT_QPA_PLATFORM=wayland to run on Wayland anyway.
qt.qpa.plugin: Could not find the Qt platform plugin "wayland" in ""
This application failed to start because no Qt platform plugin could be initialized. Reinstalling the application may fix this problem.

Available platform plugins are: xcb.

Aborted (core dumped)
[l3xforever@ls-fedora Downloads]$ QT_QPA_PLATFORM=xcb ./rpcs3.AppImage 
Debugger: 0
Warning: Ignoring XDG_SESSION_TYPE=wayland on Gnome. Use QT_QPA_PLATFORM=wayland to run on Wayland anyway.
: CommandLine Error: Option 'use-dbg-addr' registered more than once!
LLVM ERROR: inconsistency in registered CommandLine options
Aborted (core dumped)
[l3xforever@ls-fedora Downloads]$ ./rpcs3-hcorion.AppImage 
Debugger: 0
Warning: Ignoring XDG_SESSION_TYPE=wayland on Gnome. Use QT_QPA_PLATFORM=wayland to run on Wayland anyway.
: CommandLine Error: Option 'use-dbg-addr' registered more than once!
LLVM ERROR: inconsistency in registered CommandLine options
^[[AAborted (core dumped)
[l3xforever@ls-fedora Downloads]$ QT_QPA_PLATFORM=wayland ./rpcs3-hcorion.AppImage 
Debugger: 0
Warning: Ignoring XDG_SESSION_TYPE=wayland on Gnome. Use QT_QPA_PLATFORM=wayland to run on Wayland anyway.
qt.qpa.plugin: Could not find the Qt platform plugin "wayland" in ""
This application failed to start because no Qt platform plugin could be initialized. Reinstalling the application may fix this problem.

Available platform plugins are: xcb.

Aborted (core dumped)
[l3xforever@ls-fedora Downloads]$ QT_QPA_PLATFORM=xcb ./rpcs3-hcorion.AppImage 
Debugger: 0
Warning: Ignoring XDG_SESSION_TYPE=wayland on Gnome. Use QT_QPA_PLATFORM=wayland to run on Wayland anyway.
: CommandLine Error: Option 'use-dbg-addr' registered more than once!
LLVM ERROR: inconsistency in registered CommandLine options
Aborted (core dumped)
[l3xforever@ls-fedora Downloads]$ 

with PR build it does show the initial dialog box with the PR build warning, but then crashes after that just like master, so I think there's at least no change 😹

[hcorion]

Yeah looks like you're running into #13641 which is a seperate issue I'll be looking at.
If there's no change in behavior, I'm happy, at least for this PR 😓 .

[hcorion]

Testing has gone well, feels ready to merge for me.