Remove some outdated resources

collections/_evergreen/threat-modeling.html

@@ -98,7 +98,6 @@ title: What are threat models?
   <div class="col-12 col-lg-6">
     <h2>Sources</h2>
     <ul>
-      <li><a href="https://github.com/privacytools/theprivacyguide.org/blob/master/tutorials/threat-models.md">theprivacyguide.org (archived GitHub repository)</a></li>
       <li><a href="https://ssd.eff.org/en/module/your-security-plan">EFF Surveillance Self Defense: Your Security Plan</a></li>
     </ul>
   </div>