Removed the OpenGL ES 1.0 2D render implementation

In SDL3 we plan to make more use of shaders in the 2D render API, and this minimizes the number of platforms we have to consider for new features. OpenGL ES 2.0 or newer is supported on all modern iOS and Android devices.

cmake/sdlchecks.cmake

@@ -710,7 +710,6 @@ macro(CheckOpenGLES)
     if(HAVE_OPENGLES_V1)
         set(HAVE_OPENGLES TRUE)
         set(SDL_VIDEO_OPENGL_ES 1)
-        set(SDL_VIDEO_RENDER_OGL_ES 1)
     endif()
     check_c_source_compiles("
         #include <GLES2/gl2.h>