Fix unlinked border widths in WP 6.2 (#8893)

Author: Aljullu

src/Utils/StyleAttributesUtils.php

@@ -250,7 +250,7 @@ public static function get_border_width_class_and_style( $attributes ) {
 
 		$border_width_css = '';
 
-		if ( array_key_exists( 'width', ( $custom_border ) ) ) {
+		if ( array_key_exists( 'width', ( $custom_border ) ) && ! empty( $custom_border['width'] ) ) {
 			// Linked sides.
 			$border_width_css = 'border-width:' . $custom_border['width'] . ';';
 		} else {