Remove "Save as" button from Navigation block toolbar

[tellthemachines]

What problem does this address?

If a theme inserts a Navigation block as part of a template, when viewing it in the editor, a "Save as" button appears in the block toolbar, like so:

This can be confusing for users (no other blocks have a save button), and is not strictly necessary for the navigation saving flow; any changes made to the block will be saved together with other template changes when clicking the editor "Save" button.

What is your proposed solution?

Remove the "Save as" button from the Navigation toolbar.

[tellthemachines]

Closing as duplicate of #36575

[mkaz]

I'm reopening this one. The other ticket #36575 was a duplicate but included two different issues with different priorities, so better to split out. Since this ticket has better details, it'll be a better one to work off.

[getdave]

I'm looking into this one but would welcome any help.

Looks like this might be addressed by #36522?