Hide the toolbar if it has no visible items (#3654)

This PR makes the toolbar hide itself if it has no visible items.

This removes the double border beneath the tab bar when there are no
visible tools in the toolbar.

Release Notes:

- N/A
c6e44683e6Marshall Bowers committed on 12/14/2023, 6:02:27 PM· committed by GitHubparentfd133df
1 file changedLine totals unavailable