Fix error introduced in [25940] where `$public_query_vars` should have only been used as a non-existent inline docs variable in the `query_vars` filter.

Restores `$this->public_query_vars` to the `query_vars` filter in wp-includes/class-wp.php.

Props mauryaratan.
Fixes #25495. See #25719.

Built from https://develop.svn.wordpress.org/trunk@25945


git-svn-id: http://core.svn.wordpress.org/trunk@25904 1a063a9b-81f0-0310-95a4-ce76da25c4cd