Remove SDL_config.h from the public headers

The SDL headers are no longer dependent on the build configuration.

Fixes https://github.com/libsdl-org/SDL/issues/6643 and https://github.com/libsdl-org/SDL/issues/6641

src/sensor/windows/SDL_windowssensor.c

@@ -20,8 +20,6 @@
 */
 #include "../../SDL_internal.h"
 
-#include "SDL_config.h"
-
 #if defined(SDL_SENSOR_WINDOWS)
 
 #include "SDL_error.h"