Update in `RELEASE` mode script

[black7375]

Is your feature request related to a problem?

If you run ./install.sh in the directory that you installed in RELEASE mode, you cannot update it.

The solution I'd like

I think we can use the .git folder to clone. https://git-scm.com/book/en/v2/Git-on-the-Server-Getting-Git-on-a-Server

Maybe some setup work is needed (bare = false, Synchronize with files using branch and tag information).

Screenshots or video

No response

Alternatives I've considered

No response

Additional context

#532