Use shared-modules for SDL2 and Libdecor

[orowith2os]

I'm slowly going through all of Flathub to migrate manifests to use the shared modules for both Libdecor and SDL2, you are now one of my victims :D

@kowalski7cc

[flathubbot]

Started test build 10640

[flathubbot]

Build 10640 successful To test this build, install it from the testing repository:

flatpak install --user https://dl.flathub.org/build-repo/123092/com.github.k4zmu2a.spacecadetpinball.flatpakref

[flathubbot]

Started test build 10768

[flathubbot]

Build 10768 successful To test this build, install it from the testing repository:

flatpak install --user https://dl.flathub.org/build-repo/123222/com.github.k4zmu2a.spacecadetpinball.flatpakref

[flathubbot]

Started test build 10937

[flathubbot]

Build 10937 successful To test this build, install it from the testing repository:

flatpak install --user https://dl.flathub.org/build-repo/123391/com.github.k4zmu2a.spacecadetpinball.flatpakref

[kowalski7cc]

Thanks for the pull @orowith2os!

[orowith2os]

No prob. Also, why merge into beta? Wouldn't it be better to go to stable with this?

[kowalski7cc]

Usually I try (and make my fiends try) things for a couple of days in beta before merging on stable. In this case because I din't try SDL 2.26 really much, but shoul't be an issue tho.