use DEPTH24_STENCIL8 as depth attachment for render target.

I'm not sure this is even used; the backend always allocate its own internal depth/stencil buffer. There may be a final blit from the internal buffer to the render target buffer, but I haven't actually confirmed this yet

thermion_dart/lib/src/filament/src/implementation/ffi_filament_app.dart

@@ -295,9 +295,10 @@ class FFIFilamentApp extends FilamentApp<Pointer> {
       depth = await createTexture(width, height,
           flags: {
             TextureUsage.TEXTURE_USAGE_SAMPLEABLE,
-            TextureUsage.TEXTURE_USAGE_DEPTH_ATTACHMENT
+            TextureUsage.TEXTURE_USAGE_DEPTH_ATTACHMENT,
+            TextureUsage.TEXTURE_USAGE_BLIT_SRC,
           },
-          textureFormat: TextureFormat.DEPTH32F) as FFITexture;
+          textureFormat: TextureFormat.DEPTH24_STENCIL8) as FFITexture;
     }
     final renderTarget = await withPointerCallback<TRenderTarget>((cb) {
       RenderTarget_createRenderThread(