I added initial support for the upcoming SDL3. By default, it still compiles using SDL2 to prevent any problems (Basically, I added a "RETRO_USING_SDL3" define. This may need to change when SDL3 is officially released (i.e. set RETRO_USING_SDL3 to 1 and change the makefile to sdl3 instead of sdl2, but that won't be for a while). Also, for the Flatpak scripts, I changed the freedesktop SDK version to the latest version "22.08".
I added initial support for the upcoming SDL3. By default, it still compiles using SDL2 to prevent any problems (Basically, I added a "RETRO_USING_SDL3" define. This may need to change when SDL3 is officially released (i.e. set RETRO_USING_SDL3 to 1 and change the makefile to sdl3 instead of sdl2, but that won't be for a while). Also, for the Flatpak scripts, I changed the freedesktop SDK version to the latest version "22.08".