generalization of deferred commands and any_gl rendering where appropriate

src/rendering/twn_skybox.c

@@ -2,6 +2,7 @@
 #include "twn_draw_c.h"
 
 #include <SDL2/SDL.h>
+#include <stb_ds.h>
 
 static char *paths_in_use;
 
@@ -21,6 +22,14 @@ void render_skybox(void) {
         return;
 
     /* note: ownership of 'paths_in_use' goes there */
-    finally_render_skybox(paths_in_use);
+    DeferredCommand command = {
+        .type = DEFERRED_COMMAND_TYPE_DRAW_SKYBOX,
+        .draw_skybox = (DeferredCommandDrawSkybox){
+            .paths = paths_in_use
+        }
+    };
+
+    arrpush(deferred_commands, command);
+
     paths_in_use = NULL;
 }