Prevent users from hiding unpublished inlines

Summary: Fixes T9135. This is (probably) never intended and can be confusing.

Test Plan: Saw no hide button on unpublished inlines. Saw hide button on published inlines. Clicked hide button.

Reviewers: chad

Reviewed By: chad

Maniphest Tasks: T9135

Differential Revision: https://secure.phabricator.com/D14014