### Tested versions

Godot Engine v4.2.stable.official.46dc27791

### System information

Windows 10

### Issue description

When exporting to web, Godot fails with this error in the console:

> scene/main/window.cpp:884 - Attempting to make child window exclusive, but the parent window already has another exclusive child. This window: /root/@<!-- -->EditorNode@<!-- -->17120/@<!-- -->Panel@<!-- -->13/@<!-- -->ProjectExportDialog@<!-- -->559/@<!-- -->VBoxContainer@<!-- -->137/@<!-- -->AcceptDialog@<!-- -->411, parent window: /root/@<!-- -->EditorNode@<!-- -->17120/@<!-- -->Panel@<!-- -->13/@<!-- -->ProjectExportDialog@<!-- -->559, current exclusive child window: /root/@<!-- -->EditorNode@<!-- -->17120/@<!-- -->Panel@<!-- -->13/@<!-- -->ProjectExportDialog@<!-- -->559/@<!-- -->ProgressDialog@<!-- -->17444

![a](https://github.com/godotengine/godot/assets/2000051/bf9d22aa-d3fe-4e11-bff6-c387e740fe90)

This happens for newly created empty projects.


### Steps to reproduce

1. Open the attached project (or create a new project).
2. Project->Export->Export All
3. Observe the console error.  No output files are generated.


### Minimal reproduction project (MRP)

[export_test.zip](https://github.com/godotengine/godot/files/13574810/export_test.zip)

}
				Ref<Image> new_img = Image::create_empty(info.width, info.height, false, Image::FORMAT_RGBA8);
				new_img->fill(boot_bg_color);
				_blend_and_rotate(new_img, img, false);
				err = new_img->save_png(p_dest_dir + info.export_name);
			} else {
				err = da->copy(loading_screen_file, p_dest_dir + info.export_name);
			}
			if (err) {
				String err_str = String("Failed to export loading screen (") + info.preset_key + ") from path '" + loading_screen_file + "'.";
				ERR_PRINT(err_str.utf8().get_data());
				return err;
			}
		} else {
			
			Ref<Image> img = Image::create_empty(info.width, info.height, false, Image::FORMAT_RGBA8);
			img->fill(boot_bg_color);
			Ref<Image> img_bs;
			if (boot_logo_path.length() > 0) {
				img_bs = Ref<Image>(memnew(Image));
				ImageLoader::load_image(boot_logo_path, img_bs);
			}
			if (!img_bs.is_valid()) {
				img_bs = Ref<Image>(memnew(Image(boot_splash_png)));
			}
			if (img_bs.is_valid()) {
				float aspect_ratio = (float)img_bs->get_width() / (float)img_bs->get_height();
				if (info.rotate) {
					if (boot_logo_scale) {
						if (info.width * aspect_ratio <= info.height) {