Wordpress Warning: Trying to access array offset on value of type bool in /wp-includes/theme.php on line 2241

if ( is_array( $args[0] ) && isset( $_wp_theme_features['post-thumbnails'] ) ) {
            $args[0] = array_unique( array_merge( $_wp_theme_features['post-thumbnails'][0], $args[0] ) );
        }

Im getting this error after upgrading php from 7.4 to php 8.0 please help how to fix this?

source https://stackoverflow.com/questions/76681828/wordpress-warning-trying-to-access-array-offset-on-value-of-type-bool-in-wp-in