### 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
HashSet<String> features = get_features(p_preset, p_debug);
	PackedStringArray features_psa;
	for (const String &feature : features) {
		features_psa.push_back(feature);
	}
	
	uint32_t custom_resources_hash = HASH_MURMUR3_SEED;
	uint32_t custom_scene_hash = HASH_MURMUR3_SEED;
	LocalVector<Ref<EditorExportPlugin>> customize_resources_plugins;
	LocalVector<Ref<EditorExportPlugin>> customize_scenes_plugins;
	for (int i = 0; i < export_plugins.size(); i++) {
		if (export_plugins.write[i]->_begin_customize_resources(Ref<EditorExportPlatform>(this), features_psa)) {
			customize_resources_plugins.push_back(export_plugins[i]);
			custom_resources_hash = hash_murmur3_one_64(export_plugins[i]->_get_name().hash64(), custom_resources_hash);
			uint64_t hash = export_plugins[i]->_get_customization_configuration_hash();
			custom_resources_hash = hash_murmur3_one_64(hash, custom_resources_hash);
		}
		if (export_plugins.write[i]->_begin_customize_scenes(Ref<EditorExportPlatform>(this), features_psa)) {
			customize_scenes_plugins.push_back(export_plugins[i]);
			custom_resources_hash = hash_murmur3_one_64(export_plugins[i]->_get_name().hash64(), custom_resources_hash);
			uint64_t hash = export_plugins[i]->_get_customization_configuration_hash();
			custom_scene_hash = hash_murmur3_one_64(hash, custom_scene_hash);
		}
	}
	HashMap<String, FileExportCache> export_cache;
	String export_base_path = ProjectSettings::get_singleton()->get_project_data_path().path_join("exported/") + itos(custom_resources_hash);
	bool convert_text_to_binary = GLOBAL_GET("editor/export/convert_text_resources_to_binary");
	if (convert_text_to_binary || !customize_resources_plugins.is_empty() || !customize_scenes_plugins.is_empty()) {
		
		Ref<FileAccess> f = FileAccess::open(export_base_path.path_join("file_cache"), FileAccess::READ);