fix(hooks): use add_filter for block editor filter

Change add_action() to add_filter() for the
use_block_editor_for_post_type hook which is fired
via apply_filters().

Related to https://core.trac.wordpress.org/ticket/64224

Author: apermo

src/wp-admin/includes/admin-filters.php

@@ -85,7 +85,7 @@
 
 add_filter( 'heartbeat_settings', 'wp_heartbeat_set_suspension' );
 
-add_action( 'use_block_editor_for_post_type', '_disable_block_editor_for_navigation_post_type', 10, 2 );
+add_filter( 'use_block_editor_for_post_type', '_disable_block_editor_for_navigation_post_type', 10, 2 );
 add_action( 'edit_form_after_title', '_disable_content_editor_for_navigation_post_type' );
 add_action( 'edit_form_after_editor', '_enable_content_editor_for_navigation_post_type' );