This changes the references to `wp.editor` in the text widget’s JavaScript to `wp.oldEditor`, which is the new location for the old `editor` script that was previously available at `window.wp.editor`.
Follow up to [51387-51388,51390].
Props spacedmonkey, zieladam, SergeyBiryukov.
Merges [51409] to the 5.8 branch.
Fixes#53437.
Built from https://develop.svn.wordpress.org/branches/5.8@51416
git-svn-id: http://core.svn.wordpress.org/branches/5.8@51027 1a063a9b-81f0-0310-95a4-ce76da25c4cd