In non main worktree git/info/exlude is ignored.

I have huge repo (postgresql) and many worktrees for it (to not clone each time for each task).

Each worktree hash .cache/clangd folder (for clangd LSP).

Therefore `.cache` is added to .git/info/exclude .

It is honored by gitui when I run it in main worktree (which contains real .git folder), but it is ignored when gitui is running in other worktrees (where .git is just text file with path to real .git).