update SDL3 to 3.4.10.

libs/SDL3/test/testviewport.c

@@ -1,5 +1,5 @@
 /*
-  Copyright (C) 1997-2025 Sam Lantinga <slouken@libsdl.org>
+  Copyright (C) 1997-2026 Sam Lantinga <slouken@libsdl.org>
 
   This software is provided 'as-is', without any express or implied
   warranty.  In no event will the authors be held liable for any damages
@@ -183,7 +183,7 @@ int main(int argc, char *argv[])
         quit(2);
     }
 
-    sprite = LoadTexture(state->renderers[0], "icon.bmp", true);
+    sprite = LoadTexture(state->renderers[0], "icon.png", true);
     if (!sprite) {
         quit(2);
     }