FormActions ignoring css_class argument

[mschoettle]

Using FormActions with providing a css_class argument has no effect.

Usage

FormActions(
    CancelButton('/'),
    Submit('submit', _('Save')),
    css_class='d-flex justify-content-end',
),

Output

<div class="mb-3">
  <div class=""> 
    button1
    button2
  </div>
</div>

Comparing the bootstrap4 and bootstrap5 template shows that the css_class part is completely missing. In addition, I am wondering whether the inner <div> could be omitted.