Code Quality: Remove redundant variable assignment in wp_list_authors().

There is no need to initialize `$post_counts` as an empty array, since it will be overwritten directly by the filter value in the next line.

Follow-up to [54262].

Props Soean.
See #64238.

git-svn-id: https://develop.svn.wordpress.org/trunk@62091 602fd350-edb4-49c9-b593-d223f7449a82

Author: SergeyBiryukov

src/wp-includes/author-template.php

@@ -489,8 +489,7 @@ function wp_list_authors( $args = '' ) {
 	 */
 	$query_args = apply_filters( 'wp_list_authors_args', $query_args, $parsed_args );
 
-	$authors     = get_users( $query_args );
-	$post_counts = array();
+	$authors = get_users( $query_args );
 
 	/**
 	 * Filters whether to short-circuit performing the query for author post counts.