Restore overwriting queue and done.

Printing `$handles` does not work (for some reason that needs to be investigated further). Overwriting
the queue and done properties does print and has been working since 6.2 alpha. This commit restores
the overwriting properties approach.

lib/experimental/fonts-api/fonts-api.php

@@ -184,8 +184,9 @@ function wp_register_font_provider( $name, $classname ) {
 	 *                        An empty array if none were processed.
 	 */
 	function wp_print_fonts( $handles = false ) {
-		$wp_fonts   = wp_fonts();
-		$registered = $wp_fonts->get_registered_font_families();
+		$wp_fonts          = wp_fonts();
+		$registered        = $wp_fonts->get_registered_font_families();
+		$in_iframed_editor = true === $handles;
 
 		// Nothing to print, as no fonts are registered.
 		if ( empty( $registered ) ) {
@@ -195,8 +196,12 @@ function wp_print_fonts( $handles = false ) {
 		// Skip this reassignment decision-making when using the default of `false`.
 		if ( false !== $handles ) {
 			// When `true`, print all registered fonts for the iframed editor.
-			if ( true === $handles ) {
-				$handles = $registered;
+			if ( $in_iframed_editor ) {
+				$queue           = $wp_fonts->queue;
+				$done            = $wp_fonts->done;
+				$wp_fonts->done  = array();
+				$wp_fonts->queue = $registered;
+				$handles         = false;
 			} elseif ( empty( $handles ) ) {
 				// When falsey, assign `false` to print enqueued fonts.
 				$handles = false;
@@ -205,7 +210,15 @@ function wp_print_fonts( $handles = false ) {
 
 		_wp_scripts_maybe_doing_it_wrong( __FUNCTION__ );
 
-		return $wp_fonts->do_items( $handles );
+		$printed = $wp_fonts->do_items( $handles );
+
+		// Reset the API.
+		if ( $in_iframed_editor ) {
+			$wp_fonts->done  = $done;
+			$wp_fonts->queue = $queue;
+		}
+
+		return $printed;
 	}
 }