Media: Disable lazy-loading for custom logos by default.

Custom site logos are most commonly displayed above the fold, so lazy-loading is unnecessary.

Props demetris, khag7, johnbillion, rebasaurus, audrasjb.
Fixes #50933.

git-svn-id: https://develop.svn.wordpress.org/trunk@48870 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-includes/general-template.php

@@ -1000,6 +1000,7 @@ function has_custom_logo( $blog_id = 0 ) {
  *
  * @since 4.5.0
  * @since 5.5.0 Added option to remove the link on the home page with `unlink-homepage-logo` theme support.
+ * @since 5.5.1 Disabled lazy-loading by default.
  *
  * @param int $blog_id Optional. ID of the blog in question. Default is the ID of the current blog.
  * @return string Custom logo markup.
@@ -1019,6 +1020,7 @@ function get_custom_logo( $blog_id = 0 ) {
 	if ( $custom_logo_id ) {
 		$custom_logo_attr = array(
 			'class'   => 'custom-logo',
+			'loading' => false,
 		);
 
 		$unlink_homepage_logo = (bool) get_theme_support( 'custom-logo', 'unlink-homepage-logo' );