Media: add a class to the <script> tag for the JSON encoded playlist data so it can be easily selected in WPPlaylistView. Props SergeyBiryukov, fixes #29383

git-svn-id: https://develop.svn.wordpress.org/trunk@29660 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-includes/media.php

@@ -1399,7 +1399,7 @@ function wp_playlist_shortcode( $attr ) {
 	}
 	?></ol>
 	</noscript>
-	<script type="application/json"><?php echo json_encode( $data ) ?></script>
+	<script type="application/json" class="wp-playlist-script"><?php echo json_encode( $data ) ?></script>
 </div>
 	<?php
 	return ob_get_clean();