Follows #19266, #8553, Close#18553, now there are only three `Run..(&RunOpts{})` functions.
* before: `stdout, err := RunInDir(path)`
* now: `stdout, _, err := RunStdString(&git.RunOpts{Dir:path})`
This module is merged from https://github.com/go-gitea/git which is a Go module to access Git through shell commands. Now it's a part of gitea's main repository for easier pull request.