* The minimum version of Qt is now 5.x and to enable Qt6, Qt gets disabled in CMake
* A lot of crashes are fixed here when a file isn't loaded and various menus are
used, like the debugger, Reset, etc. These all assumed a console was loaded, but
console is NULL if a file hasn't been loaded yet and dereferencing it causes a
crash.
* This fixes a compiler error within smsmem & smsmem-gg declaring the same variable,
most likely because newer GCC is more picky about that.
* Remove test; line from sdl/config.c I didn't look to see where that came from,
but it causes the build to fail.
* There's still as small issue with Qt6 that Qt5 doesn't seem to have, where it
gives the central widget a resizer handle. However, on a tiling window manager,
like i3, this causes issues if the resizer is used.
