Multisite: Do not prime site meta caches unless necessary.

Props spacedmonkey.
Fixes #46357. See #46167.


git-svn-id: https://develop.svn.wordpress.org/trunk@44926 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-includes/user.php

@@ -676,8 +676,9 @@ function get_blogs_of_user( $user_id, $all = false ) {
 
 	if ( ! empty( $site_ids ) ) {
 		$args = array(
-			'number'   => '',
-			'site__in' => $site_ids,
+			'number'                 => '',
+			'site__in'               => $site_ids,
+			'update_site_meta_cache' => false,
 		);
 		if ( ! $all ) {
 			$args['archived'] = 0;