Fix "Open a file or project to get started" placeholder text not always shown (#26044)
Felix Packard
created
Check that there are no `visible_worktrees` rather than checking
`worktrees` when deciding whether to display the "Open a file or project
to get started" text
Closes #25395
Release Notes:
- Fixed the "Open a file or project to get started" message not always
showing after all buffers have been closed