Method update

packages/platform-wechat/src/EngineBridge.ts:219–223

* 更新逻辑

(deltaTime: number)

     * 更新逻辑
     */
    update(deltaTime: number): void {
        if (this._wasmInstance?.exports.update) {
            this._wasmInstance.exports.update(deltaTime);
        }
    }

    /**
     * 销毁引擎