Option ['role' => 'form'] is not necessary for Form::create()

[mixable]

What you did

Create a form by using FormHelper::create(). This results in a form tag <form ... role='form'> ... </form> as the method FormHelper::create() uses the default option 'role' => 'form' to create form tags (see line 409)

Expected Behavior

No 'role' attribute in form tags, as 'role' is not necessary. According to MDN web docs, [...] The HTML <form> element is sufficient to tell assistive technologies that there is a form. [...].

Actual Behavior

For forms created this way, the PageSpeed Insights raise a warning as follows:

I would suggest to remove the default value of the role attribute of line 409 to get a valid html document.