Editor: Fix register_block_type does not recognise ancestor block setting

When registering block through PHP, using `register_block_type` function, newly introduced `ancestor` block setting in `block.json` was not recognised. It worked though, when block is registered from JavaScript.

Props lovor, annezazu.
Fixes #56184.




git-svn-id: https://develop.svn.wordpress.org/trunk@53718 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-includes/blocks.php

@@ -286,6 +286,7 @@ function register_block_type_from_metadata( $file_or_folder, $args = array() ) {
 		'title'           => 'title',
 		'category'        => 'category',
 		'parent'          => 'parent',
+		'ancestor'        => 'ancestor',
 		'icon'            => 'icon',
 		'description'     => 'description',
 		'keywords'        => 'keywords',