Themes: Remove caching todo from get_uploaded_header_images().

Remove the note to introduce caching to `get_uploaded_header_images()` as caching has since been introduced to `WP_Query` and therefore `get_posts()`. The comment is out of date.

Props audrasjb, desrosj, flixos90, mukesh27, pbearne, pbiron, sachinrajcp123, sergeybiryukov, swissspidy, westonruter, whyisjake.
See #49446, #63168.

Built from https://develop.svn.wordpress.org/trunk@60979


git-svn-id: http://core.svn.wordpress.org/trunk@60315 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/theme.php

@@ -1500,7 +1500,6 @@ function header_image() {
 function get_uploaded_header_images() {
 	$header_images = array();
 
-	// @todo Caching.
 	$headers = get_posts(
 		array(
 			'post_type'  => 'attachment',

wp-includes/version.php

@@ -16,7 +16,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '6.9-alpha-60978';
+$wp_version = '6.9-alpha-60979';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.