add support for selects on the elements API

Author: MaggieCabrera

src/wp-includes/class-wp-theme-json.php

@@ -629,11 +629,13 @@ class WP_Theme_JSON {
 		// The block classes are necessary to target older content that won't use the new class names.
 		'caption' => '.wp-element-caption, .wp-block-audio figcaption, .wp-block-embed figcaption, .wp-block-gallery figcaption, .wp-block-image figcaption, .wp-block-table figcaption, .wp-block-video figcaption',
 		'cite'    => 'cite',
+		'select'  => '.wp-element-select',
 	);
 
 	const __EXPERIMENTAL_ELEMENT_CLASS_NAMES = array(
 		'button'  => 'wp-element-button',
 		'caption' => 'wp-element-caption',
+		'select'  => 'wp-element-select',
 	);
 
 	/**