### 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
String current_version = VERSION_FULL_CONFIG;
	String template_path = EditorPaths::get_singleton()->get_export_templates_dir().path_join(current_version).path_join(template_file_name);
	if (FileAccess::exists(template_path)) {
		return template_path;
	}
	
	if (err) {
		*err += TTR("No export template found at the expected path:") + "\n" + template_path + "\n";
	}
	return String();
}
bool EditorExportPlatform::exists_export_template(String template_file_name, String *err) const {
	return find_export_template(template_file_name, err) != "";
}
Ref<EditorExportPreset> EditorExportPlatform::create_preset() {
	Ref<EditorExportPreset> preset;
	preset.instantiate();
	preset->platform = Ref<EditorExportPlatform>(this);
	List<ExportOption> options;
	get_export_options(&options);
	for (const ExportOption &E : options) {
		preset->properties.push_back(E.option);
		preset->values[E.option.name] = E.default_value;
		preset->update_visibility[E.option.name] = E.update_visibility;
	}
	return preset;
}
void EditorExportPlatform::_export_find_resources(EditorFileSystemDirectory *p_dir, HashSet<String> &p_paths) {