Add wp_scrub_utf8() to inputs of string and ident methods

Agent-Logs-Url: https://github.com/sirreal/wordpress-develop/sessions/5418c5d6-d4e2-4e30-8060-8ad768d4b1c1

Co-authored-by: sirreal <[email protected]>

Author: Copilot

src/wp-includes/css-api/class-wp-css-builder.php

@@ -16,6 +16,7 @@ abstract class WP_CSS_Builder {
 	 * @return string CSS ident token text.
 	 */
 	public static function ident( string $value ): string {
+		$value  = wp_scrub_utf8( $value );
 		$result = '';
 		$length = strlen( $value );
 
@@ -89,6 +90,7 @@ public static function ident( string $value ): string {
 	 * @see https://www.w3.org/TR/css-syntax-3/#escaping
 	 */
 	public static function string( string $value ): string {
+		$value   = wp_scrub_utf8( $value );
 		$escaped = strtr(
 			$value,
 			array(