The example code in the PHPDoc comment for the HTML Tag Processor class
previously showed calling `next_tag()` with an array containing a `class`
key, which should have been `class_name`. This patch fixes this by using
the appropriate `class_name` key.
Props dmsnell, gaambo, crstauf, atachibana, audrasjb, krupalpanchal.
Fixes#59891.
Built from https://develop.svn.wordpress.org/trunk@57116
git-svn-id: http://core.svn.wordpress.org/trunk@56627 1a063a9b-81f0-0310-95a4-ce76da25c4cd
b5ac702f60