Taxonomy: add taxonomy for user pattern categories.

Adds a `wp_pattern_category` taxonomy linked to the `wp-block` object.

Props glendaviesnz, kebbet, desrosj, mamaduka.
Fixes #59379.


git-svn-id: https://develop.svn.wordpress.org/trunk@56642 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-includes/taxonomy.php

@@ -222,6 +222,27 @@ function create_initial_taxonomies() {
 			'show_in_rest'      => false,
 		)
 	);
+
+	register_taxonomy(
+		'wp_pattern_category',
+		array( 'wp_block' ),
+		array(
+			'public'             => true,
+			'publicly_queryable' => false,
+			'hierarchical'       => false,
+			'labels'             => array(
+				'name'           => _x( 'Pattern Categories', 'taxonomy general name' ),
+				'singular_name'  => _x( 'Pattern Category', 'taxonomy singular name' ),
+			),
+			'query_var'          => false,
+			'rewrite'            => false,
+			'show_ui'            => true,
+			'_builtin'           => true,
+			'show_in_nav_menus'  => false,
+			'show_in_rest'       => true,
+			'show_admin_column'  => true,
+		)
+	);
 }
 
 /**