Script Loader: Add support for `font-display: optional`.

This adds `optional` to the list of valid `font-display` values that can be used when validating webfonts.

Props merel1988, asafm7, mukesh27.
Fixes #58454.

Built from https://develop.svn.wordpress.org/trunk@56314


git-svn-id: http://core.svn.wordpress.org/trunk@55826 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/script-loader.php

@@ -3399,7 +3399,7 @@ function _wp_theme_json_webfonts_handler() {
 		}
 
 		// Check the font-display.
-		if ( ! in_array( $webfont['font-display'], array( 'auto', 'block', 'fallback', 'swap' ), true ) ) {
+		if ( ! in_array( $webfont['font-display'], array( 'auto', 'block', 'fallback', 'optional', 'swap' ), true ) ) {
 			$webfont['font-display'] = 'fallback';
 		}
 

wp-includes/version.php

@@ -16,7 +16,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '6.4-alpha-56313';
+$wp_version = '6.4-alpha-56314';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.