Themes: A11y: Merge omitted changes to support focus-visible.

Merge PHP changes to ensure that `focus` doesn't match `focus-visible` in `WP_Theme_JSON`, overlooked in previous merge. Follow up to [59854].

Props huubl, joemcgill, joedolson.
Fixes #62906.

git-svn-id: https://develop.svn.wordpress.org/trunk@60055 602fd350-edb4-49c9-b593-d223f7449a82

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

@@ -2906,7 +2906,11 @@ class WP_Theme_JSON {
 			array_filter(
 				$element_pseudo_allowed,
 				static function ( $pseudo_selector ) use ( $selector ) {
-					return str_contains( $selector, $pseudo_selector );
+					/*
+					 * Check if the pseudo selector is in the current selector,
+					 * ensuring it is not followed by a dash (e.g., :focus should not match :focus-visible).
+					 */
+					return preg_match( '/' . preg_quote( $pseudo_selector, '/' ) . '(?!-)/', $selector ) === 1;
 				}
 			)
 		);