Posts, Post Types: Enable revisions for the wp_block post type.

This allows site owners to take advantage of revisions while broader improvements to block management and reusable blocks are explored.

Props matveb, audrasjb, desrosj.
Fixes #53072.

git-svn-id: https://develop.svn.wordpress.org/trunk@50835 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-includes/post.php

@@ -305,6 +305,7 @@ function create_initial_post_types() {
 			'supports'              => array(
 				'title',
 				'editor',
+				'revisions',
 			),
 		)
 	);