Spam Span breaks link attributes ("data-spamspan" is not removed)

Problem/Motivation

Using the spam span filter, the following markup:

      <a class="item icon-combo icon-combo--linked align-middle icon-combo--ico-position-left" href="mailto:{{- mail -}}" target="_blank">
        <i class="icon-combo__icon ico ico-mail ico--lg bg-white text-black ico--circled ico--center" aria-hidden="true" title="{{ 'Mail'|t }}"></i>
        <div class="icon-combo__text-wrapper">
          <div class="icon-combo__text">{{ email }}</div>
        </div>
      </a>

becomes this, so its broken:

<a href="mailto:" data-spamspan-class="item icon-combo icon-combo--linked align-middle icon-combo--ico-position-left" data-spamspan-target="_blank">
        <i class="icon-combo__icon ico ico-mail ico--lg bg-white text-black ico--circled ico--center" aria-hidden="true" title="E-Mail"></i>
        <div class="icon-combo__text-wrapper">
          <div class="icon-combo__text"><a href="mailto:info@webks.de" class="spamspan">info@webks.de</a></div>
        </div>
      </a>

Steps to reproduce

Proposed resolution

Remaining tasks

User interface changes

API changes

Data model changes