Ensure the private function _wp_render_title_tag() is marked for internal usage only.

See #30469.


git-svn-id: https://develop.svn.wordpress.org/trunk@30615 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-includes/general-template.php

@@ -718,6 +718,9 @@ function get_bloginfo( $show = '', $filter = 'raw' ) {
  *
  * @since 4.1.0
  * @access private
+ * @internal
+ *
+ * @see wp_title()
  */
 function _wp_render_title_tag() {
 	if ( ! current_theme_supports( 'title-tag' ) ) {