Fix "texture not initialized" error preventing video from playing

Closes #57153

modules/theora/video_stream_theora.cpp

@@ -337,6 +337,7 @@ void VideoStreamPlaybackTheora::set_file(const String &p_file) {
 		Ref<Image> img;
 		img.instantiate();
 		img->create(w, h, false, Image::FORMAT_RGBA8);
+		texture->create_from_image(img);
 
 	} else {
 		/* tear down the partial theora setup */