gl_device: Use a more robust way to use strict context mode

Instead of checking a environment variable which may not actually
exist or is just wrong, ask QT if it's running on the wayland
platform.

src/yuzu_cmd/emu_window/emu_window_sdl2_gl.cpp

@@ -104,6 +104,8 @@ EmuWindow_SDL2_GL::EmuWindow_SDL2_GL(InputCommon::InputSubsystem* input_subsyste
         exit(1);
     }
 
+    strict_context_required = strcmp(SDL_GetCurrentVideoDriver(), "wayland") == 0;
+
     SetWindowIcon();
 
     if (fullscreen) {