Don't pass `&mut Workspace` when closing items in a `Pane`

This allows closing items via actions even in the `TerminalPanel`
where the `Pane` is not directly owned by a `Workspace`.
02066afb0eAntonio Scandurra committed on 5/9/2023, 9:45:39 AMparent506f978
4 files changedLine totals unavailable