Docs: Add missing parameter and return notations to the DocBlock for `_wp_sanitize_utf8_in_redirect()`.

See #32246.


git-svn-id: https://develop.svn.wordpress.org/trunk@35980 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-includes/pluggable.php

@@ -1270,6 +1270,9 @@ function wp_sanitize_redirect($location) {
  * @access private
  *
  * @see wp_sanitize_redirect()
+ *
+ * @param array $matches RegEx matches against the redirect location.
+ * @return string URL-encoded version of the first RegEx match.
  */
 function _wp_sanitize_utf8_in_redirect( $matches ) {
 	return urlencode( $matches[0] );