How can I add my script to admin using script-loader.php?

I think you’e are only registering it with:

$scripts->add( 'user-profile-validator', ...)

but not enqueueing it.

Check e.g. how wp_register_script() is a wrapper for the WP_Scripts::add() method.

Additionally add:

wp_enqueue_script( 'user-profile-validator' );

in the relevant admin file to enqueue it or add it as a dependency for another enqueued script.

Note that password-strength-meter is a dependency for the user-profile script:

$scripts->add( 
    'user-profile', 
    "/wp-admin/js/user-profile$suffix.js", 
    array( 'jquery', 'password-strength-meter', 'wp-util' ), 
   false, 
   1 
);

that’s enqueued with :

wp_enqueue_script( 'user-profile' );

in the backend.