Help/About: Remove `.hidden` class when the Help Tab panel is displayed.

It is obviously more logical and semantic to remove the `hidden` class when the panel is displayed. Plus, it prevents from weird behavior occurring when plugins also use the `hidden` class to hide stuff.

Props grabmedia, SergeyBiryukov, helen, sabernhardt, costdev, audrasjb.
Fixes #27697.

Built from https://develop.svn.wordpress.org/trunk@54177


git-svn-id: http://core.svn.wordpress.org/trunk@53736 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-admin/js/common.js

@@ -617,7 +617,7 @@ window.screenMeta = {
 		 * @return {void}
 		 */
 		panel.slideDown( 'fast', function() {
-			panel.trigger( 'focus' );
+			panel.removeClass( 'hidden' ).trigger( 'focus' );
 			button.addClass( 'screen-meta-active' ).attr( 'aria-expanded', true );
 		});
 
@@ -646,6 +646,7 @@ window.screenMeta = {
 			button.removeClass( 'screen-meta-active' ).attr( 'aria-expanded', false );
 			$('.screen-meta-toggle').css('visibility', '');
 			panel.parent().hide();
+			panel.addClass( 'hidden' );
 		});
 
 		$document.trigger( 'screen:options:close' );

wp-includes/version.php

@@ -16,7 +16,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '6.1-alpha-54176';
+$wp_version = '6.1-alpha-54177';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.