toggle_visibility on macOS focuses the lastest created tab

[bobrik]

Steps to reproduce:

1. Open a bunch of tabs in Ghostty.
2. Switch to any tab that is not the latest one created.
3. Switch to a different app with cmd+tab.
4. Trigger toggle_visibility and see Ghostty activated with the expected tab (good).
5. Trigger toggle_visibility to go back the the previous app.
6. Trigger toggle_visibility and see Ghostty activated with the latest created tab (bad).

[mitchellh]

Thanks #5690