For dequeuing and enqueuing scripts/styling on login, you can follow this syntax.

Please make sure that the ID is similar to your declaration. If you're unable to find it, kindly reach out to the plugin author for assistance.

function tirarScripts() {

    wp_dequeue_style( 'slate-js' );

}

add_action( 'login_enqueue_scripts', 'tirarScripts' );