Repositories with git-dir and work-dir should't create .git file in working directory

Reproduction steps

Repository.Init("/working/path", "/git/path");

Expected behavior

For most cases the whole point of doing this separation of working directory and git directory is to avoid the existence of .git file/folder in working directory

Actual behavior

The repo_is_worktree in repository.c of libgit2, should not checking for gitdir in working directory.
In config file, in git directory there is a field worktree = /working/path which could be used to find out which is the working directory.

My suggestion would be, in private Repository constructor to get the worktree value from config file in git-directory and pass it to the Proxy.git_repository_set_workdir in Repository class
instead of reading the value from options that were given from caller.
Future improvement would be not event passing the working directory, because it can be extracted from config file.

Hope to hear soon your opinion on this
Max

从 Repository.Init 和私有的 Repository 构造函数开始，然后检查 Proxy.git_repository_set_workdir 附近的 Repository.cs。将该路径与 src/repository.c 中的 repo_is_worktree 和 gitdir 处理进行比较，并按描述使用 Git 目录配置中的 worktree 值。使用分离的工作路径和 Git 路径重现该问题，并确认初始化不再在工作目录中创建 .git 文件。