Docs: Update a link to the Custom Elements spec in `force_balance_tags()` docblock.

This changeset replaces a link to the outdated W3C specs on Custom Elements with a link to the corresponding WhatWG specification.

See #54729.

Built from https://develop.svn.wordpress.org/trunk@53204


git-svn-id: http://core.svn.wordpress.org/trunk@52793 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/formatting.php

@@ -2549,7 +2549,7 @@ function force_balance_tags( $text ) {
 	 * REPL like `php -a`.
 	 *
 	 * @see https://html.spec.whatwg.org/#elements-2
-	 * @see https://w3c.github.io/webcomponents/spec/custom/#valid-custom-element-name
+	 * @see https://html.spec.whatwg.org/multipage/custom-elements.html#valid-custom-element-name
 	 *
 	 * @example
 	 * ~# php -a

wp-includes/version.php

@@ -16,7 +16,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '6.0-beta1-53203';
+$wp_version = '6.0-beta1-53204';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.