Block Editor: Use a unique name for the nonce of the custom fields toggle form.

Avoids a browser warning for having two elements with a non-unique id `#_wpnonce` on the post edit screen.

See #23165.
Fixes #51483.
Props vandestouwe, Mista-Flo.
Built from https://develop.svn.wordpress.org/trunk@50255


git-svn-id: http://core.svn.wordpress.org/trunk@49900 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-admin/includes/post.php

@@ -2303,7 +2303,7 @@ function the_block_editor_meta_boxes() {
 	<?php the_block_editor_meta_box_post_form_hidden_fields( $post ); ?>
 	</form>
 	<form id="toggle-custom-fields-form" method="post" action="<?php echo esc_attr( admin_url( 'post.php' ) ); ?>">
-		<?php wp_nonce_field( 'toggle-custom-fields' ); ?>
+		<?php wp_nonce_field( 'toggle-custom-fields', 'toggle-custom-fields-nonce' ); ?>
 		<input type="hidden" name="action" value="toggle-custom-fields" />
 	</form>
 	<?php foreach ( $locations as $location ) : ?>

wp-admin/post.php

@@ -339,7 +339,7 @@ switch ( $action ) {
 		exit;
 
 	case 'toggle-custom-fields':
-		check_admin_referer( 'toggle-custom-fields' );
+		check_admin_referer( 'toggle-custom-fields', 'toggle-custom-fields-nonce' );
 
 		$current_user_id = get_current_user_id();
 		if ( $current_user_id ) {

wp-includes/version.php

@@ -13,7 +13,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '5.7-beta1-50238';
+$wp_version = '5.7-beta1-50255';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.