possiblepromise

I also think this might work. If you replace line 129 of jetpack/modules/contact-form.php with this:

add_action( 'init', [\Automattic\Jetpack\Forms\ContactForm\Util::class, 'register_pattern'] );

That looks to be the only place the deprecated function is used as far as I can tell.

Also having this problem. Had to downgrade Jetpack and disable auto-updates to prevent it from happening again.