### Godot version

any version after 74458b6

### System information

Linux x64, but likely irrelevant

### Issue description

OpenXR action maps are not properly exported in recent builds of Godot 4: the `.res` file is small and does no longer seem to contain anything of use. In-game, no actions are passed on to OpenXR (obviously).

I bisected the issue down to https://github.com/godotengine/godot/commit/74458b6e9bed0f28db3374c7406eacbcf4b09b9d, which was merged in #70377.

### Steps to reproduce

1. Delete any previous export files (`.godot/exported/*/*.pkg`)
2. Perform an export (I did one for Android, but it likely works with anything)
3. Observe OpenXR actions not working in the export (error spam 'sync_action_sets: Condition "active_sets.size() == 0"'), and the exported action map file being very small (`.godot/exported/*/*.pkg`, from a few tens of kilobytes down to 296 bytes)

### Minimal reproduction project

Any OpenXR project can be used, such as https://github.com/BastiaanOlij/godot4_openxr_demo
}
		idx++;
	}
	if (convert_text_to_binary || !customize_resources_plugins.is_empty() || !customize_scenes_plugins.is_empty()) {
		
		String fcache = export_base_path.path_join("file_cache");
		Ref<FileAccess> f = FileAccess::open(fcache, FileAccess::WRITE);
		if (f.is_valid()) {
			for (const KeyValue<String, FileExportCache> &E : export_cache) {
				if (E.value.used) { 
					String l = E.key + "::" + E.value.source_md5 + "::" + itos(E.value.source_modified_time) + "::" + E.value.saved_path;
					f->store_line(l);
				}
			}
		} else {
			ERR_PRINT("Error opening export file cache: " + fcache);
		}
		for (Ref<EditorExportPlugin> &plugin : customize_resources_plugins) {
			plugin->_end_customize_resources();
		}
		for (Ref<EditorExportPlugin> &plugin : customize_scenes_plugins) {
			plugin->_end_customize_scenes();
		}
	}
	
	Vector<String> custom_list;
	if (!p_preset->get_custom_features().is_empty()) {
		Vector<String> tmp_custom_list = p_preset->get_custom_features().split(",");
		for (int i = 0; i < tmp_custom_list.size(); i++) {
			String f = tmp_custom_list[i].strip_edges();