Increase depth to 24

Author: misl6

kivy/core/window/_window_sdl3.pyx

@@ -156,14 +156,14 @@ cdef class _WindowSDL3Storage:
 
     def _set_sdl_gl_common_attributes(self):
         SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER, 1)
-        SDL_GL_SetAttribute(SDL_GL_DEPTH_SIZE, 16)
+        SDL_GL_SetAttribute(SDL_GL_DEPTH_SIZE, 24)
         SDL_GL_SetAttribute(SDL_GL_STENCIL_SIZE, 8)
         SDL_GL_SetAttribute(SDL_GL_RED_SIZE, 8)
         SDL_GL_SetAttribute(SDL_GL_BLUE_SIZE, 8)
         SDL_GL_SetAttribute(SDL_GL_GREEN_SIZE, 8)
 
         config_alpha_size = Config.getint('graphics', 'alpha_size')
-        SDL_GL_SetAttribute(SDL_GL_ALPHA_SIZE, 0)
+        SDL_GL_SetAttribute(SDL_GL_ALPHA_SIZE, config_alpha_size)
 
         SDL_GL_SetAttribute(SDL_GL_ACCELERATED_VISUAL, 1)