turn off html5 validation in form builder

form-builder-html5off.php

<?php
// in form-builder.inc
$forms->addHookBefore('FormBuilderProcessor::render', null, 'hookRenderForm');

function hookRenderForm(HookEvent $event) {
  $processor = $event->object;
  $form = $processor->getInputfieldsForm();
  $form->attr('novalidate', '1'); 
}

// or using InputfieldForm

$forms->addHookBefore('InputfieldForm::render', null, 'hookRenderForm');

function hookRenderForm(HookEvent $event) {
  $form = $event->object;
  $form->attr('novalidate', '1'); 
}