bump copyright year in footer of landing page

Author: cicirello

index.html

@@ -328,7 +328,7 @@ <h3>Related Publications</h3>
 </article>
 <footer>
 <small><a rel="nofollow" href="https://www.cicirello.org/e/">Contact</a></small>
-<div id="copyright"><small>Copyright &copy; 2005-<span itemprop="copyrightYear">2023</span> <a href="https://www.cicirello.org/">Vincent A. Cicirello</a>.</small></div>
+<div id="copyright"><small>Copyright &copy; 2005-<span itemprop="copyrightYear">2024</span> <a href="https://www.cicirello.org/">Vincent A. Cicirello</a>.</small></div>
 </footer>
 </body>
 </html>