update Twitter/X icon

Author: hauten

_includes/header.html

@@ -68,7 +68,7 @@
           <a class="nav-link text-azure" href="https://github.com/LLNL/llnl.github.io"><i class="fa fa-regular fa-github fa-lg d-none d-lg-inline" aria-hidden="true"></i><span class="d-lg-none">LLNL GitHub</span></a>
         </li>
         <li class="nav-item">
-          <a class="nav-link text-azure" href="https://twitter.com/LLNL_OpenSource"><i class="fa fa-regular fa-twitter fa-lg d-none d-lg-inline" aria-hidden="true"></i><span class="d-lg-none">LLNL Twitter</span></a>
+          <a class="nav-link text-azure" href="https://twitter.com/LLNL_OpenSource"><i class="fa-brands fa-x-twitter fa-lg d-none d-lg-inline" aria-hidden="true"></i><span class="d-lg-none">LLNL Twitter</span></a>
         </li>
       </ul>
     </div>
@@ -146,8 +146,8 @@
           <a class="nav-link ps-4" href="https://github.com/LLNL/llnl.github.io"><i class="fa fa-regular fa-github fa-lg d-none d-lg-inline" aria-hidden="true"></i><span class="d-lg-none">LLNL GitHub</span></a>
         </li>
         <li class="nav-item">
-          <a class="nav-link ps-4" href="https://twitter.com/LLNL_OpenSource"><i class="fa fa-regular fa-twitter fa-lg d-none d-lg-inline" aria-hidden="true"></i><span class="d-lg-none">LLNL_OpenSource Twitter</span></a>
-        </li>
+          <a class="nav-link ps-4" href="https://twitter.com/LLNL_OpenSource"><i class="fa-brands fa-x-twitter fa-lg d-none d-lg-inline" aria-hidden="true"></i><span class="d-lg-none">LLNL_OpenSource Twitter</span></a>
+        <li><i class="fa-brands fa-x-twitter"></i></li>
       </ul>
     </div>
 </header>