Docs: Document `aria-live` and `hidden` in `safecss_filter_attr()`.

In [56603], support was added for `aria-live` and `hidden` attributes in `safecss_filter_attr()`.

This adds a `@since` annotation to document this change.

Follow-up to [56603].

Props mukesh27.
See #57791.
Built from https://develop.svn.wordpress.org/trunk@56608


git-svn-id: http://core.svn.wordpress.org/trunk@56120 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/kses.php

@@ -2631,6 +2631,7 @@ function safecss_filter_attr( $css, $deprecated = '' ) {
  * @since 5.0.0 Added support for `data-*` wildcard attributes.
  * @since 6.0.0 Added `dir`, `lang`, and `xml:lang` to global attributes.
  * @since 6.3.0 Added `aria-controls`, `aria-current`, and `aria-expanded` attributes.
+ * @since 6.4.0 Added `aria-live` and `hidden` attributes.
  *
  * @access private
  * @ignore

wp-includes/version.php

@@ -16,7 +16,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '6.4-alpha-56607';
+$wp_version = '6.4-alpha-56608';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.