REST API: Fix check for has_archive inclusion.

Props dlh, audrasjb, mukesh27.
Fixes #56618.

git-svn-id: https://develop.svn.wordpress.org/trunk@54288 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-includes/rest-api/endpoints/class-wp-rest-post-types-controller.php

@@ -198,7 +198,7 @@ public function prepare_item_for_response( $item, $request ) {
 			$data['hierarchical'] = $post_type->hierarchical;
 		}
 
-		if ( rest_is_field_included( 'hierarchical', $fields ) ) {
+		if ( rest_is_field_included( 'has_archive', $fields ) ) {
 			$data['has_archive'] = $post_type->has_archive;
 		}