Depreciating Python 2 / Use pyinstaller/py2app for MacOS builds

As you've probably noticed, the installer breaks fairly often due to making a change which works on Python 3, but which doesn't work on Python 2.

We've been supporting Python 2 for MacOS users, as Python 2 comes pre-installed for them, and we don't want to make them install Python 3 on their system (it would complicate the install process, and also may alter their system setup)

One way around this would be to use a tool like [pyinstaller](https://www.pyinstaller.org/) or [py2app](https://py2app.readthedocs.io/en/latest/) to generate a standalone installer/app which the user can just run. However doing so would probably require quite a bit of testing, as I suspect some things our installer currently does (like writing to a folder adjacent to the executable) will break in this configuration.

While developers on Windows/Linux can't do the builds on their own computers, Github Actions supports MacOS as an environment, so once it's setup properly it should be OK to maintain.

I'm mainly opening this issue in case any MacOS users/developers want to figure out some distribution method for the installer on MacOS. It probably won't happen any time soon, but I thought I should at least make an issue for it.

该 issue 是关于使用 pyinstaller 或 py2app 创建一个独立的 macOS 安装程序，以替代当前依赖 Python 2 的安装程序。首先检查现有安装程序代码，了解其文件写入和执行流程。在 macOS 环境（可能使用 GitHub Actions）中测试使用 pyinstaller 构建一个简单的独立应用程序。“完成”意味着一个可工作的独立安装程序，不会破坏现有功能，需要对文件操作进行彻底测试。

由索引模型根据 Issue 内容生成。